UNIX for Dummies Questions & Answers

Hi ,

I have a script which has multiple awk and sed commands like below.

Code:

 
First one :- 
find /root/src/  -name "*csv" -size 0 -exec rm {} \;

Second one: -
ls *SRE*.txt > SRT_TRAN.dat
 
rm *asr*.txt
 
Third one :-
 
find /root/src/ -name '*.csv' | while read FILENAME ;
do
awk -F, -v fn="${FILENAME##*/}" '{print fn, $0}' OFS="," "$FILENAME" > "${FILENAME}.txt"
done

What I am trying to do is execute the second command if first command is succesfull , execute the thrid command if second command is sucesfull, some times I will not have any files with *SER* and *asr*, in these cases i don't want the script to fail., it should come out sucessfully with out any error code and the subsequent script should not execute.

Please tell me how to do this.

Regards,
Shruthi

In general you can do

Code:

command || exit 1

so whenever command returns a nonzero exit status, your program exits.

Or just once, at the top of your shell, do

Code:

set -e

and your program will exit whenever any program has a nonzero exit status.

This depends on the program's exit status, though, if the program wasn't aware of any error that won't do it. So it really depends on what you mean by 'fail'. Does 'fail' for your first command mean 'find zero files'? And so forth. Tell me what you're trying to do, not the way you want to do it...

I don't understand your need, please clarify.
But maybe this can help :
If you want to ignore the error message that are displayed, you can just add the redirection of the error output to the null file. example:

Code:

rm *asr*.txt 2>/dev/null

Regarding the dependencies, you can use "if/then/elif/else/fi" or "case $VAR in .../condition) ...;;/esac" block to manage the dependencies, also see || and && operator