Need a better understanding of shell scripts

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Understanding the difference between individual BASH login scripts

Hello... and thanks in advance for reading this or offering me any assistance I'm trying to understand specific differences between the various login scripts... I understand the differences between interactive vs non-interactive and login vs non-login shells... and that's not where my question...

2. Shell Programming and Scripting

Trouble understanding shell scripting (mostly wsname)

Am still learning Scripting and I come across a build command that I don't really understand if /local/bin/wsname 2>/dev/null; then base="`/local/bin/wsname`" export base fi if ; then /local/bin/wsname exit 1 fi WSNAME="$base"/ can some one in light me to what...

3. Shell Programming and Scripting

Understanding Shell Scripting

Hi Gurus, Im new to Shell scripting. I have a shell script which basically sends an email when called thorugh my ETL tool. Wanted to understand the its functionality in detail. Would be great it any one can explain what exactly the commands to #!/bin/sh # Dummy UUCP rmail command for...

4. IP Networking

Help understanding iproute2 and tc scripts

Hi all, I am new to linux routing and would like to keep a possible running dialog about some scripts I have been studying and what the different parts of them mean. We are using Openwrt backfire along with openvpn and Swyx as VoIP. My goal is to eventually implement some QoS using dsmark, but...

5. Shell Programming and Scripting

Problem with the shell script for understanding

Can Anybody please tell me the meaning of the script: #!/bin/sh str=$@ echo $str | sed 's/.*\\//' exit 0

6. Shell Programming and Scripting

shell script behavior is strange or I'm not understanding

Hi I have wrote the small script, where $SRC=$HOME the input file is simple text file having directories in my $SRC on pre line desktop download myfiles games #!/bin/bash FILENAME=$1 ERROR_LOG="$SRC/err.$$.log" while read line do echo "########## strat Gmake $line...

7. Shell Programming and Scripting

Understanding a Shell Script

Hi Guys, I am absolutely a newbie to Solaris 8.0. Following is a piece of code in a script (/bin/sh). Can anybody help me in deciphering this ? Please see my questions after the script code - _____________________________________________________ /bin/rm -f mycron crontab -l | grep -v...

8. Shell Programming and Scripting

Understanding a Simple Shell Script

#! /usr/bin/ksh old=$1 new=$2 for file in *.$old ; do mv $file ${file%$old}$new done exit 0 This script i got from the forum. script changes the extension of the files say example a.txt to a.doc b.txt to b.doc c.txt to c.doc d.txt to d.doc this scipt works fine but i am not...

9. Shell Programming and Scripting

Need help on understanding the Shell and AWK scripts

Hello Friends, I am new to the scripting & have to analyze bunch of regular production scripts. It has .ksh which calls on the .awk script having many functions I need to understand and debug the scripts ASAP Can anybody please let me know as how can I debug, I want to see the flow of code...

10. UNIX for Dummies Questions & Answers

Understanding System Vish startup scripts

I'm trying to get a clear picture of how startup scripts are executed during bootup. When run-level N is entered, the scripts in /rcN.d are executed. I understand that the S* scripts are executed in numerical order during bootup. What I don't understand is if the K* scripts are executed...

LEARN ABOUT DEBIAN

checkbashisms

CHECKBASHISMS(1)					      General Commands Manual						  CHECKBASHISMS(1)

NAME

       checkbashisms - check for bashisms in /bin/sh scripts

SYNOPSIS

       checkbashisms script ...
       checkbashisms --help|--version

DESCRIPTION

       checkbashisms, based on one of the checks from the lintian system, performs basic checks on /bin/sh shell scripts for the possible presence
       of bashisms.  It takes the names of the shell scripts on the command line, and outputs warnings if possible bashisms are detected.

       Note that the definition of a bashism in this context roughly equates to "a shell feature that is not required to be supported  by  POSIX";
       this means that some issues flagged may be permitted under optional sections of POSIX, such as XSI or User Portability.

       In  cases  where  POSIX	and  Debian  Policy  disagree, checkbashisms by default allows extensions permitted by Policy but may also provide
       options for stricter checking.

OPTIONS

       --help, -h
	      Show a summary of options.

       --newline, -n
	      Check for "echo -n" usage (non POSIX but required by Debian Policy 10.4.)

       --posix, -p
	      Check for issues which are non POSIX but required to be supported by Debian Policy 10.4 (implies -n).

       --force, -f
	      Force each script to be checked, even if it would normally not be (for instance, it has a bash or non POSIX shell shebang or appears
	      to be a shell wrapper).

       --extra, -x
	      Highlight lines which, whilst they do not contain bashisms, may be useful in determining whether a particular issue is a false posi-
	      tive which may be ignored.  For example, the use of "$BASH_ENV" may be preceded by checking whether "$BASH" is set.

       --version, -v
	      Show version and copyright information.

EXIT VALUES

       The exit value will be 0 if no possible bashisms or other problems were detected.  Otherwise it will be the sum of the following error val-
       ues:

       1      A possible bashism was detected.

       2      A file was skipped for some reason, for example, because it was unreadable or not found.	The warning message will give details.

SEE ALSO

       lintian(1).

AUTHOR

       checkbashisms  was originally written as a shell script by Yann Dirson <dirson@debian.org> and rewritten in Perl with many more features by
       Julian Gilbey <jdg@debian.org>.

DEBIAN
								 Debian Utilities						  CHECKBASHISMS(1)

Shell Programming and Scripting