error handling - Catching all bad signals for called commands in Bash script -

we creating bash script build server. want ensure when execute bash command inside script, returns signal of 0. if not, want execution stop. our solution far do:

#some command if [ $? -ne 0 ] ;     #handle error fi 

after every command cause problem. makes code quite long , doesn't seem elegant. use bash function, perhaps. although working $? can bit tricky, , still have call function after every command. there better way? i've looked @ trap command seems signal handling bash script writing, not commands call.

the robust, canonical way of doing is:

#!/bin/bash die() {   local ret=$?   echo >&2 "$*"   exit "$ret" }  ./configure  || die "project can't configured" make         || die "project doesn't build" make install || die "installation failed"  

the fragile, convenient way of doing set -e:

#!/bin/bash set -e     # script exit in many (but not all) cases if command fails  ./configure make make install 

or equivalently (with custom error message):

#!/bin/bash # called many (but not all) commands fail trap 'ret=$?; echo >&2 "failure on line $lineno, exiting."; exit $ret' err  ./configure make make install 

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for latter two, script not exit command part of conditional statement or &&/||, while:

backup() {   set -e   scp backup.tar.gz user@host:/backup   rm backup.tar.gz } backup 

will correctly avoid executing rm if transfer fails, later inserting feature this:

if backup   mail -s "backup completed successfully" user@example.com fi 

will make backup stop exiting on failure , accidentally delete backups.