I'd like a few volunteers to take a test that I've put
together for an "Introduction to Perl" class that I teach.
If you are a beginner or recent "graduate" of an intro
course and have a few minutes, would you time yourself
taking this test and send me the results?
================================================================
I don't usually give quizes at the end of class, but a
client of mine has requested it. (Required it in fact. No
test, no payment!)
Because I don't want the test to be a bother at the end of
the course, I've created my own objectives for the test:
The final test for "Introduction to Perl"
* will reinforce that the students have covered and
practiced the objectives;
* will allow students to demonstrate their mastery of
introductory skills (rather than the deviousness of a
seasoned instructor);
* will serve as a concise review of course hilights;
* will stimulate final in-class "fill-in" questions;
* will uncover areas that are weak, or have been quickly
forgotten, to focus personal study;
* remind students of how much they learned in class;
* convince students that their time investment created
value for them, their group, and their company.
The test I created is appended below. Please write down
your start time and completion time and post it as a
follow-up to this message or email me a reply with a
self-assesment for your level relative to an "Introduction
to Perl" class.
Thank you very much for your assistance,
Michael Wolf
/====================================================================\
| \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / |
|==V== ==V== ==V== ==V== ==V== ==V== ==V== ==V== ==V== ==V==|
| / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ |
\====================================================================/
Unless otherwise directed, fill in the blank.
======================================================================
| Sigils and data types |
======================================================================
Sigil Variable type
===== =============
$ _____________
@ _____________
% _____________
& _____________
* _____________
======================================================================
| Special variables |
======================================================================
Briefly describe (less than 10 words) the use of these variables.
$0
$1, $2, $3...
@ARGV
$ARGV
$_
@_
$!
%ENV
======================================================================
| Quotes |
======================================================================
Syntactic
Sugar Meaning Generic Interpolates
================================================================
____ Literal q// No
____ Literal qq/ Yes
____ External command execution qx// Yes
Word list generation qw// No
RE match m// Yes
RE substitution s/// Yes
Character translation tr/// No
RE quote qr// Yes
======================================================================
| open operator |
======================================================================
Here is a Perl common idiom that requires a sucessful file
handle creation before continuing.
open PW, "/etc/passwd"
or die "Cannot open password file: $!";
Briefly (less than 5 words) describe its parts.
1. open
2. PW
3. "/etc/passwd"
4. die
5. $!
================
# Open file for input.
$data_file = "sales.ca";
open DATA, "________________" or die "Cannot open input file: $!";
# Open file for output (truncate).
$out_file = "commisions.ca";
open OUT, "________________" or die "Cannot open output file: $!";
# Open file for output (append).
$log_file = "status.log";
open LOG, "________________" or die "Cannot open log file: $!";
# Open pipe for input to Perl.
$ps_cmd = "ps -au | grep msrw";
open PS, "________________" or die "Cannot open status pipe: $!";
# Open pipe for output from Perl.
$lp_cmd = "nl | pr -l60 -h'my report' | lp -d pr1";
open LP, "________________" or die "Cannot open printer pipe: $!";
======================================================================
| binary operators |
======================================================================
operator string numeric
===========================================
equal to ____ _____
not equal to ____ _____
less than ____ _____
greater than ____ _____
less than or equal to ____ _____
greater than or equal to ____ _____
comparison ____ _____
======================================================================
| truth |
======================================================================
Any value that is not false is true. What 3 values indicate
false?
numeric --
string --
other --
======================================================================
| shell interaction |
======================================================================
Perl from shell
1. How is a perl program invoked from a shell (e.g. ksh, sh, bash)?
Shell from Perl
1. What *quotes* are used to invoke a shell (or other executable) from
Perl, collecting its STDOUT?
2. What *operator* is used to invoke a shell (or other executable)
from Perl, using the same STDOUT as Perl?
======================================================================
| hygeine |
======================================================================
1. How do you specify the -w flag inside a Perl file?
======================================================================
| Array iteration |
======================================================================
This code illustrates a c-style loop, using $i as an index variable.
my $i;
my @language = qw(Perl C VisualBasic KornShell FORTH);
for ($i = 0; $i < @language; $i++) {
my $lang = $language[$i];
print "I can program in $lang.\n";
}
Create a similar loop without using $i, in a more Perlish style.
my @language = qw(Perl VisualBasic KornShell FORTH);
___________________________________ {
print "I can program in $lang.\n";
}
======================================================================
| Hash iteration |
======================================================================
%aphorism = (
roses => red,
violets => purple,
sugar => "sweet, like maple syrple"
);
Fill in the missing pieces to iterate over the hash.
==> The first blank will set $key to each of the keys of the hash
(e.g. roses, violets, sugar).
==> The second blank will set $value appropriately.
foreach ________________________________ {
_______________________;
print "$key...$value\n";
}
======================================================================
| command line arguments |
======================================================================
What do the following command line arguments mean?
-w
-e
-i
-p -n
======================================================================
| operators |
======================================================================
Name that Perl operator:
________ open a file or pipe creating a filehandle
________ close a filehandle
________ chomp the trailing newline from a scalar string
________ determine the length (element count) of an array
________ read (scalar or list) from a filehandle
________ add scalar(s) to right side (high index) end of array
________ remove scalar(s) to right side (high index) end of array
________ add scalar(s) to left side (low index) end of array
________ remove scalar(s) to left side (low index) end of array
________ reverse a list
________ sort a list
________ extract a list of hash keys
________ extract a list of hash values
________ delete an element from a hash
________ print to a filehandle (STDOUT by default)
________ print a formatted string to a filehandle (STDOUT by default)
________ split a string at RE into a list
________ join a list with a string into a string
________ warn user with message to STDERR
________ exit after warning user with message to STDERR
________ return from a subroutine or eval block
________ call the system
======================================================================
| Regular Expressions |
======================================================================
Supply the repetition quantifier for these convenience quantifiers:
* {___,___}
+ {___,___}
? {___,___}
Briefly describe (less than 5 words) these flags
/i
/g
/x
/o
/====================================================================\
| \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / |
|==V== ==V== ==V== ==V== ==V== ==V== ==V== ==V== ==V== ==V==|
| / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ |
\====================================================================/
--
Michael R. Wolf
All mammals learn by playing!
[EMAIL PROTECTED]
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