How to check the exit status using an if statement

Question

I was wondering what would be the best way to check the exit status in an if statement in order to echo a specific output   I m thinking of it being  if      -eq 1   then    echo  blah blah blah  fi   The issue I am also having is that the exit statement is before the if statement simply because it has to have that exit code  Also  I know I m doing something wrong since the exit would obviously exit the program

User · Answer

Note that exit codes    0 are used to report error  So  it s better to do   retVal    if    retVal -ne 0    then     echo  Error  fi exit  retVal   instead of    will fail for error codes  gt  1 retVal    if    retVal -eq 1    then     echo  Error  fi exit  retVal

User · Answer

You could try to find out if    is empty by using the said script below    Code that may fail here if   -z  quot    quot    then       echo  quot Code if not failed quot  else       echo  quot Code if failed quot  fi

User · Answer

Every command that runs has an exit status   That check is looking at the exit status of the command that finished most recently before that line runs   If you want your script to exit when that test returns true  the previous command failed  then you put exit 1  or whatever  inside that if block after the echo   That being said if you are running the command and wanting to test its output using the following is often more straight-forward   if some command  then     echo command returned true else     echo command returned some error fi   Or to turn that around use   for negation  if   some command  then     echo command returned some error else     echo command returned true fi   Note though that neither of those cares what the error code is  If you know you only care about a specific error code then you need to check    manually

User · Answer

Alternative to explicit if statement  Minimally   test    -eq 0    echo  something bad happened   Complete   EXITCODE    test  EXITCODE -eq 0  amp  amp  echo  something good happened     echo  something bad happened    exit  EXITCODE

User · Answer

For the record  if the script is run with set -e  or    bin bash -e  and you therefore cannot check    directly  since the script would terminate on any return code other than zero   but want to handle a specific code   gboffis comment is great   some command    error code    if    quot   error code  quot  -eq 2    then

User · Answer

If you are writing a function  which is always preferred  you should propagate the error like this  function         if some command  then         echo worked     else         return    fi    This will propagate the error to the caller  so that he can do things like function  amp  amp  next as expected

User · Answer

Just to add to the helpful and detailed answer   If you have to check the exit code explicitly  it is better to use the arithmetic operator             this way   run some command         0    amp  amp    printf   s n   Command exited with non-zero   exit 1      Or  use a case statement   run some command  ec       grab the exit code into a variable so that it can                            be reused later  without the fear of being overwritten case  ec in     0         1  printf   s n   Command exited with non-zero   exit 1          do something else   esac     Related answer about error handling in Bash    Raise error in a Bash script

User · Answer

is a parameter like any other  You can save its value to use before ultimately calling exit   exit status    if    exit status -eq 1    then     echo  blah blah blah  fi exit  exit status

User · Answer

Using zsh you can simply use  if      false   -eq 1     then echo  quot yes quot   fi  When using bash  amp  set -e is on you can use  false    exit code    if      exit code  -ne 0     then echo   exit code   fi

[bash] How to check the exit status using an if statement

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