Then let's call it a shortcoming.
It looks like -x mode uses stderr, and can conflict with redirection in the shell code.
It can get messy, yes.
This is also an issue for bash ...
... but since it does not trace redirections, the destination of the trace won't change mid-command.
Quote:
Originally Posted by MadeInGermany
Then, why stderr and not another file descriptor?
I would assume because stderr is known to be reserved for diagnostic and error messages, not data. If an alternative file descriptor were chosen, the possibility for a collision would still exist.
Corona688 makes an excellent point:
Quote:
Originally Posted by Corona688
Being 'clever' about it would make obvious things, like redirecting a trace's output into a file, difficult.
Cleverness would include attempting to detect and handle a collision between the internal tracing descriptor and a script's redirections.
I've been playing around with sed for a few days now and find that regular expressions never work inside sed s/// on Mac OS 10.2.5. Has anyone else bumped up against this problem?
For example, the "sed" segment of the following always fails no matter how items are escaped:
cd... (12 Replies)
Is this a bug in ksh on HPUX 11i or is read impromperly documented?
INPUT
Thu Jan 18 09:14:52 PST : CIFS: Virus Detected - File ONTAP_ADMIN$\vol\vol0\DDD\Ventana\Strattoni\Race Stuff\Rumor.exe in share DDD accessed by client CLIENT (111.11.11.111) running as user USER is infected. The filer... (3 Replies)
Hi All,
I am using Red Hat Linux on my servers. The problem that I am facing is, sometimes the /opt usage on the server shows used percentage as 100% , when actually it is simply 20%.
When I reboot the system, it comes back to 20%.Is this a bug in the system or my settings have gone wrong... (1 Reply)
#!/bin/bash
if then
#echo "infinite loop"
exit 0
fi
when I run this file I get the following error:
./test_infinite_loop: line 5: syntax error near unexpected token `fi'
./test_infinite_loop: line 5: `fi'
:confused: (4 Replies)
Hi
I am new to this Scripting process and would like to know How can i write a ksh script that will call other ksh scripts and write the output to a file and/or email.
For example
-------
Script ABC
-------
a.ksh
b.ksh
c.ksh
I need to call all three scripts execute them and... (2 Replies)
Hello,
Im using the g++(g++ Ubuntu/Linaro 4.4.4-14ubuntu5 4.4.5) and im trying to compile a small snippet code and got into an endless loop.I recompiled that in VS2010 under Windows 7 and the answer is as expected.so i wonder is this a bug of g++?here is my code.
#include<iostream>
using... (5 Replies)
Discussion started by: homeboy
5 Replies
LEARN ABOUT DEBIAN
shell-quote
SHELL-QUOTE(1p) User Contributed Perl Documentation SHELL-QUOTE(1p)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$SHELL -c". This doesn't work as intended:
ssh host touch 'hi there' # fails
It creates 2 files, hi and there. Instead, do this:
cmd=`shell-quote touch 'hi there'`
ssh host "$cmd"
This gives you just 1 file, hi there.
process find output
It's not ordinarily possible to process an arbitrary list of files output by find with a shell script. Anything you put in $IFS to
split up the output could legitimately be in a file's name. Here's how you can do it using shell-quote:
eval set -- `find -type f -print0 | xargs -0 shell-quote --`
debug shell scripts
shell-quote is better than echo for debugging shell scripts.
debug() {
[ -z "$debug" ] || shell-quote "debug:" "$@"
}
With echo you can't tell the difference between "debug 'foo bar'" and "debug foo bar", but with shell-quote you can.
save a command for later
shell-quote can be used to build up a shell command to run later. Say you want the user to be able to give you switches for a command
you're going to run. If you don't want the switches to be re-evaluated by the shell (which is usually a good idea, else there are
things the user can't pass through), you can do something like this:
user_switches=
while [ $# != 0 ]
do
case x$1 in
x--pass-through)
[ $# -gt 1 ] || die "need an argument for $1"
user_switches="$user_switches "`shell-quote -- "$2"`
shift;;
# process other switches
esac
shift
done
# later
eval "shell-quote some-command $user_switches my args"
OPTIONS --debug
Turn debugging on.
--help
Show the usage message and die.
--version
Show the version number and exit.
AVAILABILITY
The code is licensed under the GNU GPL. Check http://www.argon.org/~roderick/ or CPAN for updated versions.
AUTHOR
Roderick Schertler <roderick@argon.org>
perl v5.8.4 2005-05-03 SHELL-QUOTE(1p)