Execution of a program called by a shell called by crontab returns code 127

Question

I'm stuck with the following (simple) problem : I want a script to be executed every 10 minutes. This script calls executable files. I use crontab and ksh on a AIX 5.3 system.

The script makes use of relative paths, but changing the executable path to absolute didn't make any difference. So, after a few tries and this answer, I came up with the following crontab entry (*/10 doesn't work)

rs14:/home/viloin# crontab -l
0,10,20,30,40,50 * * * * cd /home/viloin/cardme/bin && /bin/ksh myScript.ksh

here is the script :

#!/bin/ksh
Main(){
 printf "executed in : %s\n" $(pwd);
 executableFile 2>/dev/null 1>&2;
 exeResult=$?; # expected return value : 90
 printf "%s\n" $exeResult;
}
Main;

Here is the output when I run the command manually :

rs14:/home/viloin/cardme/bin# cd /home/viloin/cardme/bin && /bin/ksh myScript.ksh
executed in : /home/viloin/cardme/bin
90

And finally the output when crontab runs it for me (from mail) :

 Subject: Output from cron job cd /home/viloin/cardme/bin && /bin/ksh myScript.ksh, [email protected], exit status 0
Cron Environment:
 SHELL = /usr/bin/sh
 PATH=/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/sbin:/usr/java14/jre/bin:/usr/java14/bin
 CRONDIR=/var/spool/cron/crontabs
 ATDIR=/var/spool/cron/atjobs
 LOGNAME=viloin
 HOME=/home/viloin
Your "cron" job executed on rs14.saprr.local on Wed Aug 24 11:50:00 CEST 2016
cd /home/viloin/cardme/bin && /bin/ksh myScript.ksh
produced the following output:
executed in : /home/viloin/cardme/bin
127
*************************************************
Cron: The previous message is the standard output
 and standard error of one of your cron commands.

My file myScript.ksh has all rights :

rs14:/home/viloin/cardme/bin# ll -al myScript.ksh
-rwxrwxrwx 1 viloin cardme 174 Aug 24 10:54 myScript.ksh

To make sure that my executableFile is not really exiting with code 127, I used the echo binaries, renamed it and I have the same behavior (Except that it returns 0 instead of 90 when I run the command manually).

What is causing this difference between manually typing the command and asking crontab to do it for me ?

• Ulrich Schwarz: Often, it's PATH. What happens if you run env -i myScript.ksh manually?
• Etsitpab Nioliv: @Ulrich Schwarz It shows the correct output, no 127 exit code.
• Ulrich Schwarz: Is your executableFile something that might reasonably expect to be run interactively and would fail if it's not connected to a terminal?
• Etsitpab Nioliv: I don't really understand your question, but i did cp /bin/echo ./executableFile to make sure the program is not returning 127 for any reason. So my executable is echo, nothing more, and calling echo; should return 0
• glenn jackman: change your shell script to provide a full or relative path to the executable: ./executableFile ... -- in interactive use, you either have . or the cardme/bin/directory in your PATH: that will not be true in cron's environment.

Answer 1

change your shell script to provide a full or relative path to the executable:

./executableFile ...

In interactive use, you must either have . or the cardme/bin directory in your PATH: that will not be true in cron's environment.

• Etsitpab Nioliv: Thanks again. My executableFile (the original one) used PATH variables, so I changed my crontab entry to 0,10,20,30,40,50 * * * * . $HOME/.profile && cd /home/viloin/cardme/bin && /bin/ksh myScript.ksh This change fixed the previous issue too since my PATH is now correct for cron
• glenn jackman: Good job. cron problems almost always are environment-related.
• glenn jackman: you might be able to use */10 instead of 0,10,20,30,40,50 -- check your crontab(5) man page.
• Etsitpab Nioliv: I can't see any reference to this notation in my man page, and editing crontab accordingly gives me the following error : crontab: error on previous line; unexpected character found in line. It looks like the AIX 5.3 implementation doesn't allow this notation.
• glenn jackman: oh, I didn't notice your aix tag