The open could also be written as
, but I find the 3 parameter form (variable, mode, "file") to be more readable. And the variable declaration is advisable here, unless you're reusing an older variable (you are using use strict;, aren't you?)
As for more intuitive, do you mean something like
If so, it's shorter, but much more unmaintainable.
Can this be done without using te system command? I have a directory with a large number of files in it, but I am interested in only the 8 most recent.
The directory looks like
-rw-rw-rw- 1 adsm adsm 13412 Sep 22 08:31 events_dump_09222005.csv.gz
-rw-rw-rw- 1 adsm adsm ... (5 Replies)
Hi,
I'm wanting to run an nslookup, dig or whatever to check for the existence of a printer. The PERL script will display the results on the screen, but I can't figure out how to capture the result & test the value. Any ideas will be greatly appreciated!!! Thank You (1 Reply)
I am new to scripting in Perl so I have a dumb question.
I know I can call system commands using
system("date");
But I am not able to:
1. set its output to a variable
2. run in quiet mode(no output to the screen)
The examples i have
#!/usr/bin/perl
print `date +\%y\%m\%d.\%H\%M`;... (5 Replies)
Hi guys,
got a problem with a perl cgi script over here. I need it to run a system command to get the status of a process. Unfortunately the process is owned by a specific user and only this user can get its status. So i tried running the command from the perl cgi with "su", but then i get the... (12 Replies)
HI all,
can anyone tell me what does exit status 9 from perl's system function meant.
I am using system fuction to execute a shell script as :
my $s=system ('script.sh' ,arg1 ,arg2);
print $s;
the output is 9.
Thanks in advance. !!:confused: (1 Reply)
Hi ,
Is there any way to achieve following using perl program (i.e without using system command).
1.system ("echo 'test' > /usr/spool/ship.csv");
2.system ("cat /usr/ajay_test* >> /usr/spool/RAM/work/patil.csv");
3.system("> /usr/spool/ajay.txt");
e.g
for system("rm -f... (1 Reply)
Hello experts,
I have a perl script which looks for the ARGV and then loads the data as per it.
Example.
#Checking the server to connect
if ($ARGV eq 'QA')
{
$ENV{"ORACLE_HOME"} = "/oracle/product/11.2.0";
$ENV{"PATH"} = "$ENV{'PATH'}:/oracle/product/11.2.0/bin";
... (1 Reply)
Hi Guys,
Please help me.. it is urgent. I am writing a perl script to capture command output and redirect it to a logfile.At the same i want to check the return code of the command and log it if the command is not succesful in my logfile.. Here is my code, it is working but system command inside... (2 Replies)
Hi
I have script to collect file system usage statistics from few remote unix hosts and email . On the UNIX system the column spacing is fine but the email output is not aligned properly. Any tips to fix this ? (1 Reply)
Discussion started by: new2prog
1 Replies
LEARN ABOUT MOJAVE
for
for(n) Tcl Built-In Commands for(n)
__________________________________________________________________________________________________________________________________________________NAME
for - 'For' loop
SYNOPSIS
for start test next body
_________________________________________________________________DESCRIPTION
For is a looping command, similar in structure to the C for statement. The start, next, and body arguments must be Tcl command strings,
and test is an expression string. The for command first invokes the Tcl interpreter to execute start. Then it repeatedly evaluates test
as an expression; if the result is non-zero it invokes the Tcl interpreter on body, then invokes the Tcl interpreter on next, then repeats
the loop. The command terminates when test evaluates to 0. If a continue command is invoked within body then any remaining commands in
the current execution of body are skipped; processing continues by invoking the Tcl interpreter on next, then evaluating test, and so on.
If a break command is invoked within body or next, then the for command will return immediately. The operation of break and continue are
similar to the corresponding statements in C. For returns an empty string.
Note: test should almost always be enclosed in braces. If not, variable substitutions will be made before the for command starts execut-
ing, which means that variable changes made by the loop body will not be considered in the expression. This is likely to result in an
infinite loop. If test is enclosed in braces, variable substitutions are delayed until the expression is evaluated (before each loop iter-
ation), so changes in the variables will be visible. See below for an example:
EXAMPLES
Print a line for each of the integers from 0 to 10:
for {set x 0} {$x<10} {incr x} {
puts "x is $x"
}
Either loop infinitely or not at all because the expression being evaluated is actually the constant, or even generate an error! The
actual behaviour will depend on whether the variable x exists before the for command is run and whether its value is a value that is less
than or greater than/equal to ten, and this is because the expression will be substituted before the for command is executed.
for {set x 0} $x<10 {incr x} {
puts "x is $x"
}
Print out the powers of two from 1 to 1024:
for {set x 1} {$x<=1024} {set x [expr {$x * 2}]} {
puts "x is $x"
}
SEE ALSO
break, continue, foreach, while
KEYWORDS
for, iteration, looping
Tcl for(n)