Again, my thanks to all for the help, which was my fault in not realizing
that I had used the -o switch instead of the -O switch and so was not
having my code optimized.
On the off chance that anybody was wondering why I was doing this, it was
just a test to try to determine the "best" way to see if a C string ended
with a \r, or carriage return. Why? Because sometimes people here goof up
and ftp a Windows file to the mainframe, but do it from a UNIX server.
Well, they don't, but we share an NAS box between Windows an Linux servers.
So the file on the z sometimes has an extraneous \r at the very end of the
line. One good thing this did for me was point out that I was really doing
it wrong. I found the address of the end of the string using with the code
"argv[i]+strlen(argv[i])". But the strlen() code generated actually found
the end of the string using the SRST and then converted that to an integer
(size_t), which I then converted right back to an address. So I searched
and found the strchr() routine which can find the terminating null and
returns its address. Using this function resulted in a TRT in a loop. Which
I didn't much care for. So I looked at the memchr() function. But it
requires a maximum length. Now, since I'm looking for a \0. And since a
proper C string is \0 delimited, I _ASSuMEd_ that the string was properly
delimited. This allowed me to use an arbitrary length for the memchr()
call. So I used 0x7fffffff, or 2GiB. That seems more than large enough to
me.
The code is now:
for(i=0; i<argc; i++) {
if ('\r'==*( (char *) memchr(argv[i],'\0',0x7fffffff)-1)
*( (char *) memchr(argv[i],'\0',0x7fffffff)-1) = '\0';
}
Of course, this would really be done after the fgets() call. The code
generated is lovely:
* if ('\r' == *(findend-1))
L r5,(*)uchar*(r2,r1,0)
LR r6,r5
LA r0,0
AL r6,=F'2147483647'
SRST r6,r5
JO *-4
BL @1L13
LA r6,0
@1L13 DS 0H
AHI r6,H'-1'
CLI (*)uchar(r6,0),13
BNE @1L5
* *(findend-1)='\0';
MVI (*)uchar(r6,0),0
@1L5 DS 0H
where findend is:
#define findend (char *)memchr(argv[i],'\0',0x7fffffff) // for ease to
change method
I need to cast the (void *) from memchr() to a (char *) in order to
subtract 1 from it. Of course, this can S0C4 if the string is not \0
delimited. Or it could possibly corrupt a byte of innocent storage. But
this should not happen in my planned use since fgets() should return a
pointer to a \0 delimited string or NULL. And I _will_ check for NULL.
On Sat, Feb 22, 2014 at 11:16 PM, John McKown
<[email protected]>wrote:
> Just for fun, I wrote a very small C program. I compiled it on Linux/Intel
> using GCC 4.8.2. I then got it compiled on z/OS 1.13. The program is very
> small:
>
> #include <stdlib.h>
> #include <stdio.h>
> #include <string.h>
> #undef strlen
> int main (int argc, char *argv[]) {
> int i;
> for(i=0;i<argc;i++) {
> if ('\r' == *(argv[i]+strlen(argv[i])) )
> *(argv[i]+strlen(argv[i]))='\0';
> }
> return 0;
> }
>
> <snip/>
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