Get exit code for command in bash ksh

Question

I want to write code like this   command  some command   safeRunCommand  command  safeRunCommand        cmnd  1        cmnd      if         0    then       printf  Error when executing command    command         exit  ERROR CODE    fi     But this code does not working the way I want  Where I made mistake

User · Answer

There are several things wrong with your script.

Functions (subroutines) should be declared before attempting to call them. You probably want to return() but not exit() from your subroutine to allow the calling block to test the success or failure of a particular command. That aside, you don't capture 'ERROR_CODE' so that is always zero (undefined).

It's good practice to surround your variable references with curly braces, too. Your code might look like:

#!/bin/sh
command="/bin/date -u"          #...Example Only

safeRunCommand() {
   cmnd="$@"                    #...insure whitespace passed and preserved
   $cmnd
   ERROR_CODE=$?                #...so we have it for the command we want
   if [ ${ERROR_CODE} != 0 ]; then
      printf "Error when executing command: '${command}'\n"
      exit ${ERROR_CODE}        #...consider 'return()' here
   fi
}

safeRunCommand $command
command="cp"
safeRunCommand $command

User · Answer

It should be  cmd instead of    cmd   Works fine with that on my box   Edit  Your script works only for one-word commands  like ls  It will not work for  ls cpp   For this to work  replace cmd   1    cmd with       And  do not run your script as command  some cmd   safeRun command  run it as safeRun some cmd   Also  when you have to debug your bash scripts  execute with  -x  flag   bash -x s sh

User · Answer

The normal idea would be to run the command and then use    to get the exit code  However  some times you have multiple cases in which you need to get the exit code  For example  you might need to hide it s output but still return the exit code  or print both the exit code and the output    ec          1      -h      amp  amp    shift  amp  amp  eval     gt   dev null 2 gt  amp 1  ec     echo  ec       eval     ec         This will give you the option to suppress the output of the command you want the exit code for  When the output is suppressed for the command  the exit code will directly be returned by the function   I personally like to put this function in my  bashrc file  Below I demonstrate a few ways in which you can use this       In this example  the output for the command will be   normally displayed  and the exit code will be stored   in the variable  ec     ec echo test test   echo  ec 0       In this example  the exit code is output   and the output of the command passed   to the  ec  function is suppressed     echo  Exit Code    ec -h echo test   Exit Code  0       In this example  the output of the command   passed to the  ec  function is suppressed   and the exit code is stored in   ec     ec -h echo test   echo  ec 0     Solution to your code using this function     bin bash if       ec -h  ls -l   grep p        0      then     echo  Error when executing command   grep p    ec       exit  ec  fi      You should also note that the exit code you will be seeing will be for the grep command that s being run  as it is the last command being executed  Not the ls

User · Answer

Try  safeRunCommand                 if         0    then       printf  Error when executing command    1         exit  ERROR CODE    fi

User · Answer

Below is the fixed code      bin ksh safeRunCommand       typeset cmnd        typeset ret code    echo cmnd  cmnd   eval  cmnd   ret code      if    ret code    0    then     printf  Error     d  when executing command    cmnd    ret code     exit  ret code   fi    command  ls -l   grep p  safeRunCommand   command    Now if you look into this code few things that I changed are    use of typeset is not necessary but a good practice  It make cmnd and ret code local to safeRunCommand use of ret code is not necessary but a good practice to store return code in some variable  and store it ASAP  so that you can use it later like I did in printf  Error     d  when executing command    command    ret code pass the command with quotes surrounding the command like safeRunCommand   command   If you dont then cmnd will get only the value ls and not ls -l  And it is even more important if your command contains pipes  you can use typeset cmnd      instead of typeset cmnd   1  if you want to keep the spaces  You can try with both depending upon how complex is your command argument  eval is used to evaluate so that command containing pipes can work fine   NOTE  Do remember some commands give 1 as return code even though there is no error like grep  If grep found something it will return 0 else 1    I had tested with KSH BASH  And it worked fine  Let me know if u face issues running this

[bash] Get exit code for command in bash/ksh

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