RE: Calling sequence
On Thu, 29 Apr 1999, Mullen, Patrick wrote: # Like I said from the beginning (or maybe I just thought it, # I can't remember), the example line is bad programming # so it shouldn't be done, anyway. yeah because if you miss out the spaces it becomes i+j (or whatever the variables were) and looks a right mess. -- +++ The program isn't debugged until the last user is dead. +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
Re: Allocation
On Wed, 28 Apr 1999, Amol Mohite wrote: # in main function if i have int i, j; # # can i be sure that i and j are contiguous ? does it matter? (think about it, what use would knowing if they were do you?) they could be, then again could not be. Does it depend on processor archetecture and operating system? -- +++ The program isn't debugged until the last user is dead. +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
Re: Calling sequence
On Wed, 28 Apr 1999, Amol Mohite wrote: oh goodie, more homework to do :) # In gcc, # # if i = 2; # then j = i++ + ++i; # # what is the value of j. 6. # what is the calling sequence in this case ? ++i first or i++ first ? it'd do this: i = 2 i++ /* add 1 to i and return 2 */ i = 3 ++i /* add 1 to i and return 4 */ add 2 and 4 and give you 6. # # why does fork have to return a value of zero to the child process ? if you have to ask this then you've never written a program that uses fork() and understood it. # why not -5 or -6 ? because in the switch statement you wouldn't know if you were in a parent or child. let me know what grade you got for that homework :) -- +++ The program isn't debugged until the last user is dead. +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
Re: recv
On Wed, 28 Apr 1999, Glynn Clements wrote: # # Why don't you just use fgets(), fscanf() etc? # how? don't they need a FILE pointer not a file descriptor. (this is probably # a very silly question with a very simple answer...) # See the fdopen(3) manpage. Ahhh... i see. FILE *foo; foo = fdopen (sd, "r"); /* where sd is a socket descriptor from socket() */ What's the maximum size of data you can send over a SOCK_STREAM in one go? -- +++ The program isn't debugged until the last user is dead. +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
Re: Calling sequence
On Wed, 28 Apr 1999, Glynn Clements wrote:
# In gcc,
#
# if i = 2;
# then j = i++ + ++i;
#
# what is the value of j.
#
# i++ == 2
# ++i == 3
# =j == 5
no. it's not. I typed this in:
main() { int i = 2; printf ("%d", i++ + ++i);}
and when i ran it i got 6 printed...
--
+++ The program isn't debugged until the last user is dead. +++
[EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
recv
i'm trying to communicate with a server which sends output down a socket. The server sends a code and then some text (e.g 01: Connection Refused). What i'd like to do is just recv the first 2 bytes and act on them, instead of having to recv the whole line (i don't know how long the lines of text are, they can be changed), if i do a recv for 2 bytes i'll get '01' but then the next recv will get the rest of the text won't it? i could recv 1 byte at a time, storing the characters in a buffer, until a newline was found (all output from the server ends in \n) but that sounds overly complicated. -- +++ The program isn't debugged until the last user is dead. +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
C Compilers
What are the differences between: gcc egcs pgc and which should i use? Last i tried, egcs wouldn't compile kernels. All i want is a good, quick C and C++ compiler that works 100% with all code. Also, where am i supposed to install a c compiler and how do i remove an existing one (after compiling the new one of course!)? -- +++ The program isn't debugged until the last user is dead. +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
egcs
can egcs compile kernels yet? -- +++ The program isn't debugged until the last user is dead. +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
processes
if i know the pid of a process, how can i find out it's status? (i.e running, blocked, ready, zombie, invalid pid...) -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
Re: compiling
On Sun, 11 Apr 1999, Darius Blaszijk wrote: # Recently I came across a package witch I want to use in my programs. The # package consists of a header file (interface) and a *.c source code file # (implementation). How can I use these files in my application? If I try # to compile my application the compiler gives me this message: undefined # reference. By your use of 'interface' and 'implementation' i'd say you've used modula-2 or pascal... and like those languages you must tell your C compiler to include the header file. Assuming the header is called foo.h and the source is called foo.c. Put them in the same directory as your c program (called bar.c in this example). in the top of bar.c put a line like this: (it goes along with the #include stdio.h and similar lines) #include "foo.h" this tells gcc to look in the current directory (which is what "" means. means 'look in standard include locations') then when you come to compile, type a command line like: gcc -Wall -o bar bar.c foo.c the -Wall just makes gcc really really picky about your code (a good thing). -o tells it what to call the executable (the first thing after the -o) and bar.c and foo.c are the sources to compile. You need to compile foo.c as well. If it was given as an object file (foo.o) then you'd do something slightly different ( gcc -Wall -c bar.c /* creates bar.o */ gcc -Wall -c foo.c /* creates foo.o */ gcc bar.o foo.o -o bar /* links them together into an executable called 'bar' */ ) -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
Re: array filling problem
On Sat, 10 Apr 1999, Dan Jue wrote:
# Are we allowed to assume that row-major order arrays are totally
# contiguous in memory for any platform (by your example of address
Probably not.
# a[0][4])? For arrays of structures or objects (or some other big unit),
# is it not possible for their locations in memory to be non-contiguous?
Yes.
# Also i'm assuming that you cannot access a[0][4] directly because wouldn't
# that cause an out-of-bound subscript error? So you would instead do some
No. C Does not do array bounds checking. You could quite happily run this
C program:
main(){int f[2]; f[12345]=1;}
and when you run it all you get is an ever helpful 'Bus Error'.
# manual pointer arithmetic to get that address, right?
a[0][4] is a legal array subscript. If the element you're telling it to
reference is part of the array then nothing bad will happen, if however the
array isn't stored contiguously then you may try and access memory you have
no rights to access and crash the program.
# Thanx for any response.
#
#
# Best Regards,
#
#
# * Dan Jue, CMSC UMCP *Linux '99 *
# ** ReSiTaNcE iS FuTiLe!*
#
#
#
#
--
+++ If at first you don't succeed, you must be a programmer +++
[EMAIL PROTECTED] http://www.penguinpowered.com/~a_out
Re: fledgling
On Tue, 6 Apr 1999, Glynn Clements wrote: # In no less than 5 months I will be graduating and # moving on to college. I plan to study computer # engineering. I know that I *will* be able to skip some # courses, especially if it has to deal with # programming. # # It depends upon the nature of the course. Being able to program won't # necessarily get you all that far on a Computer Science degree course; # I don't know about Computer Engineering. that's sort of what i'm doing (i'm doing BSc (hons) S/Ware Eng.) and the C programming was mainly boring, but i'm glad i did it all the same, the bit we did with pointers really helped. For some reason i'm also doing an Information Systems module which is so boring i keep falling asleep :) (it's the boring waffly side of computing, like Systems Analysis but less diagrams and more words) -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
ppp
what's the most reliable way of detecting when a ppp link is up? so far i've been looking in /proc/net/dev, but the ppp entry in that hasn't gone away and i'm nolonger online. -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
terminal
how do i turn off the cursor and make my programs accept characters typed into a terminal without you having to press enter first? I once knew, but i forgot :) -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: Type casting with malloc()
On Thu, 1 Apr 1999, holotko wrote: # My question. Do I really need to add the type cast (ObjectType *) # before the call to malloc() ? no. but gcc will warn you, if you use -Wall, about it. Doesn't do any harm leaving it in and if you miss it out gcc will add it in itself. Technically you need it because malloc returns memory cast to void *, which your data structures aren't. Makes your code more readable if you include it though. -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
strtok()
maybe it's just me, but i find this funny... (from the strtok() manpage) BUGS Never use this function. it's a fairly big bug! :) i expect there are similar things stuck to nuclear warheads (Warning! This device is hazardous to most forms of life, do not use). i'll try strsep() instead, it says it's not ANSI-C so how portable is it? (i'm not bothered about this program not working on DOS machines, just other flavours of POSIX compliant operating systems) -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: strtok()
On Mon, 29 Mar 1999, Bug Hunter wrote: # # strtok() uses a global to store its intermediate results. meaning that # you can get unexpected results if several parts of your program use it. # it uses a local static variable actually. and it is very destructive, but if you make a copy of the string you're mangling then it's ok. how efficient are the string library routines? if my program does lots of strcmp()s and strcat()s etc will it be slower than if i was to write my own versions? -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
recv
is it really inefficient and slow to recv stuff from a socket 1 byte at a time? my program reads data from a socket 1 byte at a time, checking if the character read is a newline, if it isn't then the char is copied into a char array, otherwise the recv stops and something is done with the array. then the whole thing is repeated for the next line... etc. basically i want to be able to read strings of varying length from a socket, stopping when a newline is found. -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
-D
does doing gcc -DBAR=\"foo.c\" do the same thing as gcc -DBAR='"foo.c"' which is equivalent do doing this in the source file #define BAR "foo.c" -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: poniter problem
On Fri, 26 Mar 1999, Amol Mohite wrote:
# say I have a char *c pointing to an array of 10 bytes.
you mean:
char myarray[10], *c;
c = myarray;
# When i do (int *)c++ (increment before typecast -- forget the brackets for
# nw), and equate it t an int *i then
please re-read what you type. this is full of typos and makes it really
difficult to read. Also include example code as it makes it more clear.
(int *)c++; doesn't do much except make c point at myarray[1] and return
the value typecast as an int (thus returning the character's ascii code).
# *i will return 2nd to fifth bytes as integer. Is this correct ?
no, first make i point to the array. typecasting in that way doesn't
convert the types of the elements in that array. To get the 2nd - 5th
bytes (elements) as integers you'd have to:
int cnt;
for (cnt = 1; cnt 5; cnt++)
printf ("%d\n", (int *)(c+cnt)); /* you have to do something with */
/* the typecast variables */
except why bother with pointers to array elements?
for (cnt = 1; cnt 5; cnt++)
printf ("%d\n", (int *)myarray[cnt]);
# And supose the typecase is beore the incerenent like so :
# ((int *)c)++ then *i will return 5th to 8th byes. is this correct ?
no. that would cast c to an integer and then return the next one, which is
of type char.
# aslo how is exception handling implemented ? Does the processor have
# exception registers ?
what do you mean by exceptions? things like running out of memory and
opening non-existant files, etc? to deal with these the functions that
do the file i/o, memory allocation, whatever. return values that you
check.
# Also if I have allocated a struct liek :
#
# struct {
# int i;
# char b;
# }str;
#
# which is obviously 5 butes large.
not always. it will be
sizeof (int) + sizeof (char)
which on my machine (P233) is 5 bytes. Someone running a Sun or Alpha may have
different sized variables.
# Than whenre will the proceessor allocate the next bit of memory ?
# Directly after the char b byte?
it doesn't matter where it goes. All you need to know, as a C programmer,
is that you have some struct called str which contains an integer and a
character.
Do you own a good C book? (the Kernighan Ritchie ANSI C Programming Book
is a good one. Ones that mention Turbo C, or other DOS things, aren't - for
Linux programming that is)
--
+++ If at first you don't succeed, you must be a programmer +++
[EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: container class ?
On Fri, 26 Mar 1999, Chetan Sakhardande wrote: # Also in unix, how do i set an alarm with timer less than i sec? use usleep(). -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: ???
On Mon, 22 Mar 1999, Glynn Clements wrote: # will allocate space for a `char *', but it will point to some random # memory location. The result of using dbQuery as the first argument to # sprintf() will be undetermined. The one thing of which you can be sure # is that it will write to some memory which it shouldn't be writing to. about this... if one of my programs goes a bit mad and tries to write to something it shouldn't, does the memory write actually take place? or does Linux realise before and kill the process? it creates a page fault because the memory wanted won't currently be in physical ram, Linux would go and fetch this page (if it exists), realise that the process doesn't have rights to access this page and send a SIGSEGV to the process. process then drops dead, creates a corefile and the user goes 'huh?... oh, missed the flipping in my scanf' [is that right?] -- +++ If at first you don't succeed, you must be a programmer +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: cdrom_msf and cdrom_ti question
On Sun, 21 Mar 1999, Glynn Clements wrote: # I'm using struct cdrom_ti to play audio tracks, but when I try to play # the last track (this fails on every cd) it wont't play. # Every track but the last track works, isn't that weird? # One of my ideas is that maybe it has something to do with my use of # 'ti' instead of 'msf'? # # Are you trying to specify the start of a non-existent track as the end # position? isn't the very last track on a cd the lead-out track (a sort of "This is the End, you may stop now") which can't be played? -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Porting Resources
I realize I could have wasted a few hours of my life seaching for this on my own, but I am hoping to get some personal opinions here. What are some good resources on porting DOS applications to linux? Books, web pages, FAQs, etc. I am looking for general "guides" that talk about pitfalls to watch out for, and items of the such. Thanks in advance, -James C. Lewis _ /_ _ _ _ / ) / _' _ (_/(///)(-_) (__ . (__(-((//_) PUCC Information Center Consultant [EMAIL PROTECTED] Please place all complaints in this box -- []
Re: vim or emacs c syntax
On Sun, 14 Mar 1999, Catalin Bucur wrote: # Chris wrote: # # I was wondering how to make vim do syntax highlighting for C code or emacs # and how to set tabs for code. # # Thanks # # For vim, # :syntax on and the tabstops... :set tabstop=x [where x is some number, 4 or 8 usually - 4 being a sane choice :)] -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: Missing errnos.h
On Sat, 6 Mar 1999, Henk Jan Barendregt wrote: # I'm trying to compile a code which uses a header file I haven't heard of # errnos.h # # Check your include path or otherwhise i think you've lost it somehow. # On my system (kernel 2.0.36) it's in the /usr/include directory it's called 'errno.h' (the person coding probably spelt it wrong): bigbird:~$ locate errnos.h bigbird:~$ locate errno.h /usr/include/bsd/errno.h /usr/include/errno.h and can be found in the normal include directory. #include errno.h -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: exit() ...
On Fri, 5 Mar 1999 [EMAIL PROTECTED] wrote:
# I've seen a lot of source code lately. My idea the best way to learn a
# language ...
#
# I've noticed that exit() can take a parameter. I've seen exit(0), exit(1),
# exit(2) and even exit(10). What does the parameter mean ? I can't find any
# table with its possible values ...
the number is known as an exit status and is returned to the parent of that
process (which if you run the program from a shell then the exit status is
returned to the shell).
there are no specific numbers, you can put whatever you like there. There
are a few conventions however...
0 - Normal termination
1 - abnormal termination (something bad happened and you had some sort of
error routine that called exit(1))
e.g
int main ()
{
int fd;
if (!fd = open (...))
{
perror ("open");
exit (1);
}
... rest of normal code ...
exit (0);
}
--
+++ Beware of programmers who carry screwdrivers +++
[EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
RE: Yet another beginners question ...
On Tue, 2 Mar 1999 [EMAIL PROTECTED] wrote: # My friend says that I should buy the KR but i think I read somewhere that # it's 'old C', not ANSII C. Is this correct ? no, the KR ANSI C Book is for ANSI (One I) C... I think you're confusing it with KR C which is old C. this is the book to buy: The C Programming Language (ANSI C) Brian W Kernighan Dennis M Ritchie [Prentice Hall Software Series] ISBN : 0-13-110362-8 -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: Yet another beginners question ...
On Tue, 2 Mar 1999 [EMAIL PROTECTED] wrote:
# #define LOGFILE /APPHOME/applogfile /* APPHOME is the actual home
# directory for the application */
# remove("LOGFILE");/* First remove the old logfile */
# LogFile = fopen("LOGFILE", "w");
you know how using #define's replaces whatever you #define with whatever
is after it? (#define FOO bar would go through your code and replace all
occurrences of FOO with bar)
wouldn't the above get turned into:
remove ("/APPHOME/applogfile /* APPHOME is the actual home..")
or would it strip out the comments first?
--
+++ Beware of programmers who carry screwdrivers +++
[EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: Newcomer
On Sun, 21 Feb 1999, Piero Giuseppe Goletto wrote: # As far as I know, the minix kernel is the basis from which Linus Torvalds # started writing the Linux Kernel. "and in the beginning god did type 'cp -r minix/* linux'" :) where can i get gas (the gnu assembler)? i want to compile kernel 0.0.1 just to see what it's like... -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
./configure
How do i make my own configure scripts? are they hand written or created by some special program? -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: Debugging ...
On Mon, 22 Feb 1999 [EMAIL PROTECTED] wrote:
# I have an application in wich i define for example an integer that is equal
# to 3. But I want the following adjustment to my program :
# When i wanna compile my program with the -g (debug) option, i'd like that
# the integer is equal to 2. What i want is a sort of
#
# #IFDEF __DEBUG__ THEN
#
# #ELSE
#
# Is this possible ?
well i just wrote this:
#include stdio.h
#ifdef __DEBUG__
int c = 2;
#else
int c = 3;
#endif
main() { printf ("C = %d\n", c); }
---
and if you compile it without any flags it prints 3, and if you
do
gcc -g -D__DEBUG__ foo.c -o foo
it prints 2...
the -D__DEBUG__ is important
--
+++ Beware of programmers who carry screwdrivers +++
[EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Saneness
What is a non-sane build environment? (apart from Windows and dos :) -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: your mail
On Fri, 19 Feb 1999, Nassar Carnegie wrote: # Thats all good too.., beacuse im learning C as well. I thought to learn # more from other peoples problems and programming errors by joining a C # programming mailing list. I see that this list moves kind of "slow" yeah, but this list is like a pipe, you only get stuff out of it if something has been put in to start off with. The main linux stuff goes on over at [EMAIL PROTECTED] (standard majordomo controlled list) -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
signals
Why doesn't linux have a ualarm() or sigset()? it's mildly irritating. cos if i'm writing some program that needs a continuous alarm sending i have to repeatedly call signal() and alarm() to set one up. surely there's an easier way. including bsd/signal.h just gives me an error about the file not existing but it does exist : bigbird:~# ls -l /usr/include/bsd/signal.h -rw-r--r-- 1 root root 603 Apr 12 1997 /usr/include/bsd/signal.h The Suns at university run Solaris and that's what my code ends up running on. -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: stderr
On Wed, 17 Feb 1999, David Rysdam wrote: # The second way is to close file descriptor 2, and re-open another # file/device with that number within your program. will C let you do that? cos what'd happen if you closed stdout and forgot to re-open one and then did a printf(). And you can't open random file descriptors (although if you just closed fd 2 a call to open() should use that...) -- +++ Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: memory allocation
On Thu, 18 Feb 1999, Anubhav Hanjura wrote:
# main()
# {
#
# char *filename;
# char *string =3D "this is a string";
#
# strcpy(filename,string);
# printf("filename is %s\n",filename);
# }
This _should_ break. where does *filename point?
from the strcpy() man page:
DESCRIPTION
The strcpy() function copies the string pointed to be src
(including the terminating `\0' character) to the array
pointed to by dest. The strings may not overlap, and the
destination string dest must be large enough to receive
the copy.
key part: the destination string must be large enough since *filename
is undefined then chances are you'll attempt to write to memory you don't
own and cause a SIGSEGV (segmentation fault), there is a small chance you
will access memory you do own and that is why it doesn't always break.
first make *filename point somewhere by using malloc() or turning it into
an array...
--
+++ Beware of programmers who carry screwdrivers +++
[EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Re: variable arguments
On Thu, 18 Feb 1999, Anubhav Hanjura wrote:
# I was just wondering, how is the case of variable arguments eg. in printf/scanf etc.
implemented in linux?
here's the mail i got when i posted a similar thing to this list...
--
+++ Beware of programmers who carry screwdrivers +++
[EMAIL PROTECTED] http://www.users.globalnet.co.uk/~kermit
Here's what i got sent when i asked the question...
-- Forwarded message --
Date: Wed, 9 Sep 1998 22:27:03 +0100 (BST)
[i keep my mails :) ]
From: Glynn Clements [EMAIL PROTECTED]
To: James [EMAIL PROTECTED]
Cc: Linux C Programming List [EMAIL PROTECTED]
Subject: Re: function parameters
James wrote:
how do i create a function that has an undetermined number of parameters?
By using an ellipsis (`...') in the declaration and using the
va_{start,arg,end} macros (defined in stdarg.h) to access the
parameters.
the definition for it has '...' as a parameter... what's that mean?
It means `plus any number of extra parameters'.
and if you don't know how many parameters are being passed into the
function beforehand, how do you know what the variable names are?
You don't. You need to use the va_* macros to access the additional
parameters.
You also need to be able to figure out how many parameters should have
been passed, and what their types are. printf() determines this from
the format string. Other possibilities include having a count
parameter and using a NULL argument to terminate the list (as is the
case for execl() and friends, and the XtVa* functions).
For example:
#include stdarg.h
#include stdio.h
void contrived(int count, ...)
{
va_list va;
int i;
va_start(va, count);
for (i = 0; i count; i++)
printf("%s\n", va_arg(va, char *));
va_end(va);
}
int main(void)
{
contrived(3, "hello", "there", "world");
return 0;
}
--
Glynn Clements [EMAIL PROTECTED]
Test
hello...
--
+++Beware of programmers who carry screwdrivers +++
[EMAIL PROTECTED] [Website undergoing re-design...]l.org
int a=1,b,c=2800,d,e,f[2801],g;main(){for(;b-c;)f[b++]=a/5;for(;d=0,g=c*2;c
-=14,printf("%.4d",e+d/a),e=d%a)for(b=c;d+=f[b]*a,f[b]=d%--g,d/=g--,--b;d*=b);}
Funny Fortune! (fwd)
completely off topic, out of date and ultimately not worth posting...
but funny all the same
--
+++Beware of programmers who carry screwdrivers +++
[EMAIL PROTECTED] [Website undergoing re-design...]l.org
better !pout !cry
better watchout
lpr why
santa claus north pole town
cat /etc/passwd list
ncheck list
ncheck list
cat list | grep naughty nogiftlist
cat list | grep nice giftlist
santa claus north pole town
who | grep sleeping
who | grep awake
who | grep bad || good
for (goodness sake) {
be good
}
Re: send_sig and library question
On Fri, 15 Jan 1999, Glynn Clements wrote: # send_sig() is a kernel function (kernel/exit.c). # send_sig() isn't in any library; it's a kernel function. # You can't link to it; it's a kernel function. # # You find the library first. Then you read the library's documentation, # which should tell you which functions it provides. so it's a kernel function then :) -- +++Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Hello...
is this list dead too? (what's happened to linux-admin@vger? not even majordomo is replying...) -- +++Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Re: test
On Thu, 14 Jan 1999, David Rysdam wrote: # # email!! wow... guess they turned the server back on :) -- +++Beware of programmers who carry screwdrivers +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Re: Hello...
On Fri, 15 Jan 1999, Karl F. Larsen wrote: # # James, # This list is far from dead. But it sometimes is quiet. I carry a # leatherman which has even a long nosed pliers! It's good for helping those # "Easy Open" beer cans. cool, i've just got a 'standard' sized screwdriver (the size that lets you completely dismantle a pc) i need a little pair of pliers (for picking said screws off the motherboard when i drop them in!) and i came home from work early! the computer that controls the petrol pumps died (we had a powercut and when the power came back on the computer went a 'bit' mental - pretty blue lines diagonally over the screen) nasty embedded thing. probably runs something Microsuck related :)
Re: Arrays
On Sat, 9 Jan 1999, Richard Ivanowich wrote:
# Hello all,
#
# Now i know arrays do no bound checking. How would i make it do bound
# checking?
#
# ie. int array[10];
#
# for(i=0;i=11;i++) {
# array[i]=i;
# }
for (i=0;i10;i++)
{
array[i] = i;
}
/*i.e code bound checking by hand */
--
+++Beware of programmers who carry screwdrivers +++
[EMAIL PROTECTED] [Website undergoing re-design...]l.org
Mail (fwd)
oops! i'll try sending it to the right place this time... there isn't a linux-c-programming at vger is there? -- Forwarded message -- Date: Sat, 2 Jan 1999 01:37:01 + (GMT) From: "James [on his mailserver]" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Mail in a mailspool, mails are separated by: [blank line] From someone@theiraddress the_date right? so what happens if i write this in the middle of my email: From [EMAIL PROTECTED] Mon Jan 1 00:00:00 1970 would this following text get interpreted as a separate mail? or is the stuff above somehow quoted? like dots are: . (that gets turned into '..' when sendmail sends it)
bits
i'm writing a program which can accept switches to set various things in
the program, there will be several switches (all optional) which set
some conditions in my program to either ON or OFF. To process this i was
going to:
declare a struct like this:
struct {
unsigned int file : 1; /* input from file or stdin? */
unsigned int today : 1; /* use today's date? */
...
} flags;
munch through **argv looking weather the switches are present
if they are, set the relevant things in the struct to 1, if they aren't
present, set them as zero (or init the flags struct to all zeros to start
off with, then just set the switches that are given to 1).
then in the relevant parts of the program, check if a bit was set, if it
was, do foo, if it wasn't set, do bar... etc.
anyone see a problem with this? i'll just be accessing the flags thing
like a regular struct.. i.e if (flags.file == 1) { fopen (...) } else {
fgets (stdin) };
i could use whole ints for each flag, but why waste an entire (sizeof
(int)) when i am only setting things on or off, using bits seems more
logical...
Libraries
i've written a C library (call it 'foo) and made a foo.a file using 'ar'. Now what do i do? i tried copying the file into /usr/local/lib and compiling a test program using 'gcc -Wall -lfoo test.c -o test' and it complained about undefined references to all my library routines. i also tried making a dynamic library (foo.so.1), copied it into /usr/local/lib, ran ldconfig and tried compiling it like above. This time ld complained it couldn't find the file -lfoo. i have a foo.h file which lives in /usr/local/include and contains function prototypes and #defines for all the functions used in my library.
Re: ! = -1?
On Sun, 27 Dec 1998, Colin Campbell wrote: errr wait a minute. 0 equals false any other value represents truth. You seem err crap! i ALWAYS mix it up! going to buy a post-it-note and write it down and stick it on my monitor :) to quote from my KR C book... "if it is true (that is, if expression has a non-zero value)" i'll go and sit in the corner then :) (and re-write all my c code :( ) Clear? Try checking the code through again. as some highly polished crystal that is so clear it looks like it doesn't exist.
Arrays
isn't there any way to do this:
ask user for some integer 0
make an array that big
cos i'd like to...
would this work:
int thing[0], *ptr = thing;
int in;
...
printf ("Enter a number 0:");
scanf ("%d", in);
realloc (ptr, in);
...
?
! = -1?
in C's logic, do -1 and 1 mean the same thing? i.e FALSE. 0 is the ONLY value that is interpreted as TRUE right? cos i have a function (and we'll call it foo() again :) which does something and returns -1 if there is an error and 0 if it went ok. Now if in my main() i do this: /* assume foo() returns 0 for 'it went ok!' */ int ret; ... ret = foo(); if (!ret) ... the stuff in the if loop never gets executed but if i do if (ret) ... or if (ret == -1) ... it does. oh! DH ret == -1. !ret or NOT (-1) == 0 or TRUE ret == -1. !ret AND NOT (-1) == 0 AND TRUE (as well) sometimes logic can be a bit confusing especially if you !think :) and i !was thinking (ohhh dear... what is this? 1001 cracker jokes for programmers?! - ! a !!... AAGH! who decided to use ! as NOT?!) [translated literally, using opposite english words...] sometimes logic can be a bit confusing especially if you (dont think) :) and i (wasn't) thinking (ohh dear... what is this? 1001 cracker jokes for (non-programmers) - (not) a (true)... (whay) who decided to use (not) as (true?)) yes, that is a load of gibberish, although it does nicely illustrate how what you _mean_ and what it _actually_ means can be totally different.
Re: File formats? .MID, .KAR, .ST3
On Tue, 22 Dec 1998, James [on his mailserver] wrote: On Tue, 22 Dec 1998, Dave wrote: Can anyone point me to information on file formats for the following file types: www.wotsit.com has loads of specs on file formats. oops, meant www.wotsit.org
Mobile Phones
A bit off topic, but interesting nontheless; i crashed my mobile phone! Panasonic G450, UK Vodafone it said Lo Battery, i pressed a key (probably 5) and the backlight came on, then the battery ran out and it said Phone Shutting Down and stayed that way until i removed it's battery! when i tried to power it up it didn't, had to plug the charger in... anyone else had any weird experiences with embedded programs like this? (i seem to have a knack at making things fail, it's happened to my Atari Lynx, Personal CD Player (i could make the backlight flash patterns!) and my MD recorder killed a disc for no good reason) thought embedded programs were considered relatively bug-free, afterall there's only a few states the hardware can be in...
Code formatting
should C code be formatted so that it fits into an 80 column display? i think it should because otherwise list and other viewers wrap the text which looks really nasty.
Re: egcs
On Wed, 25 Nov 1998, Glynn Clements wrote: I'm not sure if this answers your question, but then I'm not really sure exactly what your question was. i'm not sure either (it was approaching 3am and i was determined to make kernel 2.0.36 compile before i went to bed.. and i did) i've got both egcs and gcc2.whatever i downloaded in /usr/lib/gcc-lib/i586-pc-rest of this path/ and i can do gcc to use egcs or gcc -V2.thing to use the other one. It successfully compiled the kernel and is it me or is 2.0.36 quicker than previous kernels. it seemed to boot faster.
Re: mail help
On Sat, 21 Nov 1998, CyberPsychotic wrote: probably would be worth to set list-members-only posting policy. i don't see why this wasn't set anyway. What's the use of being able to post to this list if you never receive replies?
Re: indenting question
On Thu, 12 Nov 1998, Leon Breedt wrote:
-is it better to indent my source using real (\t) tabs, or should i configure
-my editor to expand tabs into spaces? i can't decide which is best :)
use tabs because when deleting the tab character (i.e you press tab in the
middle of a line by accident) the gap disappears in one, you don't have to
bash backspace 4 times.
use spaces if you are going to edit/read the file in different editors with
different tab settings, it'll ensure that the file looks the same
-and secondly, what tab stop length is recommended? 2/4/8?
2 is too small, 4 is just right, 8 is too big:
set tabstop=2:
int foo()
{
printf ("Some stuff here\n");
for (banana = 0; banana cherry; banana++)
{
printf ("more stuff");
}
}
tabstop=4:
int foo()
{
printf ("hello\n");
for (stuff...)
{
hello;
}
}
and tabstop = 8;
int foo()
{
printf ("this eats up too much space");
printf ("go any more than about");
printf ("this number of levels and it gets hard to \
fit text on one line without wrapping it");
}
--
+++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++
[EMAIL PROTECTED] [Website undergoing re-design...]l.org
Re: linked list question
On Fri, 13 Nov 1998, Glynn Clements wrote: - -Leon Breedt wrote: - - i'm working on a doubly-linked list at the moment, just one or two questions: - - i looked at the way the doubly linked list is implemented in glib, - -What is glib? the low-level GTK+ library, think it handles basic screen drawing and window stuff that GTK+ builds onto to make it's rather nice widgets. -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Re: free memory?
On Sat, 14 Nov 1998, Moshe Zadka wrote: -Decrefing with a bug? -consider the following, buggy, code: -a=malloc(10); -b=malloc(10); -free(a); -free(a); wouldn't the program stop when it reached the 2nd free because it is trying to free a NUL pointer (assuming free sets them to NUL, if not the program will surely crash as it tries to free some random memory address that it probably has no right to alter) these are the kinds of things that make programming such fun! :) (and spending 3 hours going through your source all because you typed '' instead of ''...) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Re: Magazines for low prices!
On Mon, 9 Nov 1998, magazines wrote: -To be removed from future mailings, please send an email to -mailto:[EMAIL PROTECTED]D i'm too tired to think. Can someone cook me up a procmail recipe that looks for similar strings to this (to be removed, to remove etc) in emails and stuffs these emails somewhere (i can suggest a place, but it's rude and possibly quite painful :). Most spam has this at the bottom. -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Re: Newbie Header Q's
On Sun, 8 Nov 1998, Marc Evelyn wrote: Nah. They use ed. there's bits of that in VI, :q! and all that stuff. is it as bad as edlin?
Re: My PCI modem.
On Sat, 7 Nov 1998, Canul Podkopayeva wrote: -BTW, its a PCI plug-n-play modem, I'm running 2.1.126 aargh! run for the hills! anyway, if it has Winmodem on it then it'll make a good doorstop :) have you tried running minicom or something and configuring that? modems don't require any special 'setting up' in linux, they're just there... -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Re: last question :)
On Sat, 7 Nov 1998, Leon Breedt wrote: -what's the fastest way to check for the existence of a file/directory? try and stat() it? if it fails then it doesn't exist? -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Re: file size query
On Sat, 7 Nov 1998, Leon Breedt wrote: -hi again - -is there a function similar to pascal's filesize() in ANSI C? something -that will take a pointer to a stream as parameter, and return the file -size in bytes. man stat -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Can anyone actually see this mail? None of my mails i've sent have come back to me... -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED] [Website undergoing re-design...]l.org
Mail spools
is the data in /var/spool/mail/whatever in a special order? I mean the order of the separate mail messages. Does it matter if the newest is at the head and the oldest at the tail? -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
Re: Mail
On Sat, 17 Oct 1998, Henrik Nordstrom wrote: There are two UNIX mailbox formats. Which one thats used depends on your sendmail version/configuration. Format 1. "^From " based. From Whoever@somewhere date mail data. Any line beginning with "From " is escaped to "From ". i've scanned through /var/spool/mail/root and they're all in the From [EMAIL PROTECTED] DDD MMM DD HH:MM:SS format, with a blank line before that to separate mails. If i'm playing round with user's mailboxes, do i need to somehow lock them? i'll be reading each mail out of the spool and checking it's date, if it's after a set date it gets put into a new spool, otherwise it gets left in the original spool.
Man Page Error
This is semi-on topic... (it's about a man page to do with c programming): There's an error in the GETCWD(3) manpage: NAME getcwd, get_current_dir_name, getwd - Get current working directory SYNOPSIS #include unistd.h char *getcwd(char *buf, size_t size); char *get_current_working_dir_name(void); char *getwd(char *buf); ... get_current_dir_name, which is only prototyped if __USE_GNU is defined...blah...blah... spot it? there's a function called 'get_current_dir_name' listed, but it's prototype lists it as 'get_current_working_dir_name' (which is wrong). Try typing 'man get_current_dir_name' then 'man get_current_working_dir_name' to see what i mean... these man pages came from Slackware 3.5 GPL that www.cheapbytes.com sell. -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
stat
how do i use the S_IS* macros? i want to check files to see if they really
are files or directories... all it says is
S_ISREG(m) regular file?
what's m? i've tried stating a filename, then doing:
if (S_ISREG(buf.st_rdev)) /* st_rdev seemed the most sensible */
printf ("File\n")
else
printf ("Not File\n");
but it always prints "Not File" instead of "File", even with proper files.
--
+++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++
[EMAIL PROTECTED]http://x-map.home.ml.org
Re: What's the biggest file?
On Tue, 15 Sep 1998, tempest wrote: -Hello James, - -Sorry to bother you with such a silly question, but could you give me -the URL of where you found the Linux Programmers Guide? I'd really -like to have that myself! I'm on the linux-c-programming mailing -list, in case your wondering how I knew your email. :) sunsite... (in the docs/LDP/ dir) it seems a good book, from the odd bits i've read whist it's being printed there are some interesting things : IPC, Curses etc.. -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
finding strings
wait... made it a bit more user friendly... $ grep `find -name *.c -print` -ne | less it'll now display the line numbers and pipe it into less so you can read it a page at a time. -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
File IO
how do i do file I/O in the kernel? I.e i want to read a value from a file and store it in the kernel's uptime variable... i've tried the 'normal' open() (or was it fopen(), one of the two) but it complains (i can't remember the error, but it was as though i'd not linked something in). and if i'm kernel hacking, i should get the latest development kernel right? and this is probably a silly question, but in VI how do i move lines upwards? like, see on the 4th line i added some text, and it doesn't fill the whole line, how do i suck the line below it up onto that line? i have to press return after each line because i don't have wordwrap on. -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
What's the biggest file?
thought this might help someone, wrote it whilst trying to work out where all my harddrive space had gone... $ du -bax | sort -rn +0 | less it'll display all your files and directories, sorted with the biggest first (which'll always be . so ignore the top line). It only searches the current drive (otherwise it'd go off down all your NFS links and dos mounted partitions ( = slow)) just remove the x from du if you want it to do that. it's probably really inefficiant and will probably give you a load average of 2, but never mind :) go on... show me a perl program that does the same, and only shows the bigges and smallest FILE :) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
Re: curses, colour won't work...
On Sun, 13 Sep 1998, Ken wrote: - - -On Sun, 13 Sep 1998, James wrote: - - how do i get coloured text in ncurses? i've tried making a colour pair - and attron() and attrset() but the best i got was the following in - black on flashing white (the text was 'Hello!'): - - 27462Hello! - - (i can't remember what the numbers were, but there were some numbers). - -Did you call start_color() and check it? i did... and it returned true (or whatever means 'yes! i can do colour' - -Have a good read of the Linux Programmers Guide 0.4 if you haven't -already. It has a very large section on ncurses. If you can't find -try poking around in sunsite.unc.edu or one of it's mirrors. didn't know it existed! i'll have a look. what i did keep forgetting was to call refresh()... "hey! where's my text! oi!" :) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
max dir length
just for compatabilities sake, what's the maximum number of directory entries (is it infinite?), i've picked 255 for no good reason, this sound sane? what?! suppose sending this'd help (it's been sat here all night) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
file locations
where's the 'standard' place for my program binaries to go? /usr/local/bin or /usr/bin ? and documentation should go in /usr/doc/programname manpages in /usr/man/... (and how do i write manual pages anyway?) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
flex
flex would let me parse files wouldn't it? at the moment i have a
horrendous parsing routine that contains a few gotos in it (aargh :)
and is generally really complicated ( = slow) and not nice.
What i want parsing is similar to C source (but not the same, it
contains blocks of data enclosed in {}s, has comments that start //
(but can also contain useful data) but nothing is ever more than 1
level deep, i.e
{
something
{
some more
}
}
but never any deeper. FYI the data is a Quake .MAP file)
flex'd be able to handle this wouldn't it? whenever it encounters
'something' it needs to run some code, feeding 'something' into the
code as a parameter.
--
+++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++
[EMAIL PROTECTED]http://x-map.home.ml.org
directories
forget it i've worked it out... open a dir with opendir(), have a loop that repeatedly calls readdir(). now i need repeated calls to stat() to find out the file size... -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
RE: main()
On Wed, 9 Sep 1998, Niels Hald Pedersen wrote: -If you want a pascallish structure of C programs, use function -prototypes: this is what i do... apart from making it 'nicer' for the compiler, it can also trap errors like forgetting a parameter when writing the function itself. I wasn't actually trying to make it look like pascal, i just wrote code and my style just happens to look like it (let's start another debate : What tabsize is better? 4 or 8? i use 4) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
Re: function parameters
On Wed, 9 Sep 1998, Glynn Clements wrote:
- printf ("Hello","world","\n","%d%d%d", 2, 0, 35);
-
-This isn't a legitimate printf() call. The format string has to be a
-single argument, e.g.
oops, i meant
printf ("Hello ""World ""\n"); /* No ,'s between */
so that if you have a huge printf() line, you can split it up over lines:
printf ("This is a really really long line that needs to wrap"
" in order to look nice");
(that works, i just tried it)
--
+++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++
[EMAIL PROTECTED]http://x-map.home.ml.org
Re: UNIX meteor (was RE: fsck)
On Tue, 8 Sep 1998, Niels Hald Pedersen wrote: - - -Reuters, London, February 29, 1998: -that's an unorthodox leap year, isn't it ? i'd spotted that... What happens to people born on the 29th feb? are they 1/4 age of everyone else born in their year? :) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
function parameters
how do i create a function that has an undetermined number of parameters?
i.e printf can have 1 parameter:
printf ("Hello World\n");
or many...
printf ("Hello","world","\n","%d%d%d", 2, 0, 35);
how?
the definition for it has '...' as a parameter... what's that mean? and if
you don't know how many parameters are being passed into the function
beforehand, how do you know what the variable names are?
--
+++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++
[EMAIL PROTECTED]http://x-map.home.ml.org
Re: fsck
On Tue, 8 Sep 1998, Dave wrote: -Except maybe the United States government, who still uses vacuum tubes and -discrete transistors to run its air traffic control system "If it aint broke, don't try to fix it" (oh, wait... you said vacuum tube...) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
uptime
I've been thinking about this for a while... is there some patch that'll store my pc's uptime when i reboot (so it'd really be a cumulative-uptime). -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
main()
where is the right place to put main()? before or after my function
definitions? Because i used to write Pascal code, i stick main() last
(in Pascal, the main begin..end pair must be the last function in the program).
does it matter? seems more logical to define your prototypes, write them,
then the main program.
A:
//
int main (){}
int foo(){}
int bar(){}
/*/
B:
/**/
int foo()
{
}
int bar(){}
int main(){}
/**/
--
+++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++
[EMAIL PROTECTED]http://x-map.home.ml.org
Re: fsck
On Fri, 4 Sep 1998, dreamwvr wrote: -Reuters, London, February 29, 1998: -Scientists have announced discovering a meteorite which will strike the -earth in March, 2028. Millions of UNIX coders expressed relief for being -spared the UNIX epoch "crisis" of 2038. at least when that event does happen (the number of seconds since some time in the 70's long int - that's right isn't it?) we'll have the source to fix it. Somehow a 2038 bug doesn't seem as catchy :) -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
Re: Binary
On Tue, 1 Sep 1998, Josh Muckley wrote: -You need to find the pinouts of the parallel port and then just -connect a led from a data line to a ground line. There are three -differant types of lines in your p-port. The first and most important -is DATA (out), the second is STATUS (in) and the third is CONTROL -(i/o). You can find a lot more info searching for Parallel ports and -the net. yeah, i know... already done that. It's just a pain having to specify the LEDs using hex. -- +++ Divide By Cucumber Error, Please Re-Install Universe And Reboot +++ [EMAIL PROTECTED]http://x-map.home.ml.org
Re: Binary
On Sat, 29 Aug 1998, Glynn Clements wrote: - -James wrote: - - How do you use binary numbers in C? i'm sure i once knew... - - i know you prefix 0x to numbers for Hex, 0 for octal, what's binary... - -ANSI C doesn't provide any way to specify numbers in binary. - ahh... oops! i know where i saw it, x86 assembly : mov al, 01010101b oh well, looks like i'll have to keep my calculator handy... oh, and thanks for all the replies about the usleep() thing, you can stop responding :) (i have about 20 odd replies!), but at lest replies are given... -- [EMAIL PROTECTED]http://x-map.home.ml.org
binary
uh oh, i've started another big debate :) carry on, it's interesting stuff... -- [EMAIL PROTECTED]http://x-map.home.ml.org
Re: Binary
On Sun, 30 Aug 1998, Chetan Sakhardande wrote: -No way. - -Just curious -- why? you ever seen that diagram that shows how to connect LEDs to the data lines on your parallel port? well i wanted it to flash different patterns (for no good reason) and it's 1 bit per led, 1 on, 0 off. specifying 10101010 or 11001100 instead of reaching for my hex converter would be easier. (bored programmers are the worst type! :) -- [EMAIL PROTECTED]http://x-map.home.ml.org
usleep()
why when i run the following does it wait 5 seconds then display
.\.\.\.\.\ instead of displaying . [wait 1 second] \ . [wait 1 second]...
/* start */
#include stdio.h
#include unistd.h
int main()
{
int c;
for (c = 0; c 5; c++) {
printf (".");
sleep (1);
printf ("\\");
}
return 0;
}
/* end */
--
[EMAIL PROTECTED]http://x-map.home.ml.org
Stat
i'm trying to use stat() to find out a file's size. So far i have :
/* Start Of Code */
#include sys/stat.h
#include unistd.h
#include stdio.h
int main (void)
{
int status;
struct stat *buf;
status = stat ("/root/.procmailrc", buf);
/* don't ask why i'm using my procmailrc, it's the first file */
/* i thought of */
return 0;
}
/* End Of Code */
that should have filled buf with info about that file, but how do i go about
displaying the filesize? i know it's in buf-st_size, but that's of type
off_t (what's that?) and printf() segfaults when i try to do
printf ("File is %d bytes\n", buf-st_size);
well actually i get a warning when compiling.
--
[EMAIL PROTECTED]http://x-map.home.ml.org
Re: EGG ROLLS!
On Mon, 24 Aug 1998 [EMAIL PROTECTED] wrote: -Are you tired of eating the same old american left overs? -TRY OUR BEAUTIFUL ORIENTAL DISHES AT CATHAY PEARL! - - 508-379-1188 - i live in the UK, do i get full refund if it's cold :) -- [EMAIL PROTECTED]http://x-map.home.ml.org
Re: Soundcards...
On Fri, 21 Aug 1998, luser wrote: - how can i capture the data that my soundcard produces when it makes sounds? - -Not very easily using software, you would need to use pipes and a -program to write to a file and the device file. ioclt() is used -to set sampling speed/size, it's problematic. If someone has a way -to do this I'd be interested in find out how. - -Using two sound cards with inputs and ouputs wired to together. -One recording the output of the other would be easier. oh, i forgot to mention : my soundcard (Gravis Ultrasound PnP) is Full-Duplex (can record and play at the same time - you can play a wav, and simultaneously record it to another wav). so all(!) i'd have to do is start the card playing (or have something playing into it) and at the same time sample what is coming into the card. -- [EMAIL PROTECTED]http://x-map.home.ml.org
Re: Tired with the vi/grep, who can recommend a better programming environment.
On Thu, 20 Aug 1998, Nathan Grass wrote: - I think that anyone who enters Computer Science as a student MUST have a - computer and it must have Linux. As a class project they write a new X - manager or such. - -Did I ever tell you the story of a little operating system called Minix? that's in a book available from our University Library. If there's a course on O/S design i want to do it! Linux wrote linux because he was bored. I've got Linux 0.99.0 or something on a CD, it runs off 2 floppies, doesn't know about harddrives and in the docs says "I'm not sure if Linux will ever be able to run X"... hmm. -- [EMAIL PROTECTED]http://x-map.home.ml.org
RE: Malloc()
On Mon, 10 Aug 1998, Niels Hald Pedersen wrote: -Is this true ? - -On my system, it is possible to compile/link a new (changed) version of -a program, while a copy is still running. After the link, the running -old copy no more have a valid executable, thus. How come ? because the program is probably small enough to get loaded into ram all in one go. how does linux handle files that are opened more than once? i sometimes have the same c source file open in 2 separate terminals (i use one as reference, helps when writing functions where the prototypes are right at the top, saves jumping up and down the screen all the time) one with vi, the other with less (or vi). The first copy i edit, save to, compile etc, the other is just opened. Now i know you can't do this under windows (sharing violations) so how does linux do it? -- I Like England Just Fine, But I Ain't Eating Any Of That Beef MailTo: root at kermit "dot" globalnet /dot\ co 'dot' uk De Chelonian Mobile
Patches
i want to make patches for my C programs, i know it involves using diff to make the patch, and patch to apply it but what do i do? i've read 'man diff' and it can output patches in various formats, does it matter which format i use (i don't think it does because patch works out the format when you use it) i assume you need an 'old' and a 'new' version of each file that needs patching. -- I Like England Just Fine, But I Ain't Eating Any Of That Beef MailTo: root at kermit "dot" globalnet /dot\ co 'dot' uk De Chelonian Mobile
Re: remove
On Fri, 31 Jul 1998, K.HARI.KRISHNAN wrote: //remove This doesn't work you know... Oh if only people would read the email they first got... [It's the same on ALL mailing lists] I Like England Just Fine, But I Ain't Eating Any Of That Beef MailTo: root at kermit "dot" globalnet /dot\ co 'dot' uk De Chelonian Mobile
This List
Is this list broken or something? i've had hardly any mail off it! (either that or procmail has gone a bit wonky - i'm sure it deletes mail for me! i know the default mailbox for unsorted mail disappears every so often) I Like England Just Fine, But I Ain't Eating Any Of That Beef MailTo: root at kermit "dot" globalnet /dot\ co 'dot' uk De Chelonian Mobile
Pthreads-dev
Where can i get the Pthreads-Dev package from? I need it so i can compile something (sound-recorder-0.02.tar.gz) because at the moment i get this error: bigbird:/sound-recorder-0.02# make cd src; make all; make[1]: Entering directory `/sound-recorder-0.02/src' g++ -D_REENTRANT -Wall -O3 -c record.cc g++ -D_REENTRANT -Wall -O3 -c cd-player.cc g++ -D_REENTRANT -Wall -O3 -c waveriff.cc g++ -D_REENTRANT -Wall -O3 -c pcm.cc g++ -D_REENTRANT -Wall -O3 -c commndln.cc g++ -D_REENTRANT -Wall -O3 -c dsp.cc g++ -D_REENTRANT -Wall -O3 -c dspsetting.cc g++ -D_REENTRANT -Wall -O3 -c rcfile.cc g++ -D_REENTRANT -Wall -O3 record.o cd-player.o waveriff.o pcm.o commndln.o dsp.o dspsetting.o rcfile.o -o record -lpthread /usr/i586-pc-linux-gnulibc1/bin/ld: cannot open -lpthread: No such file or directory collect2: ld returned 1 exit status make[1]: *** [record] Error 1 make[1]: Leaving directory `/sound-recorder-0.02/src' make: *** [all] Error 2 Or is it a gcc thing? bigbird:/sound-recorder-0.02# gcc --version egcs-2.90.29 980515 (egcs-1.0.3 release) (although i tried it on another pc with the older gcc and got the same error)
