How to Determine the Meaning of a Qshell Exit Status or Signal

• 0 when successful.
• 1 when unsuccessful.
• 2 when an error occurred in a script.
• 3 when there was an unexpected exception in a root shell.
• 4 when there is an unexpected exception in an exception handler for a root shell.
• 5 when there is an unexpected exception in a child shell.
• 6 when there is an unexpected exception in an exception handler for a child shell.
• 7 when descriptor 0 is not available.
• 8 when descriptor 1 is not available.
• 9 when descriptor 2 is not available.
• 10 when there is an error opening the message catalog.
• 11-125 when unsuccessful.
• 126 when a command is found; however, it cannot be invoked.
• 127 when a command cannot be found.
• >128 when a command is ended by a signal. The value is 128 plus the signal number.

When the exit status is greater than 128, the command ended by a signal. To determine the signal number, you would take the exit status received and subtract 128. For instance, a typical exit status received is 133. If 128 is subtracted, a signal number of 5 is received. In order to determine the meaning of the signal, refer to the sys/signal.h header file on IBM i. To display the header file, run the command WRKMBRPDM FILE(QSYSINC/SYS) MBR(SIGNAL) then enter Option 5 to display the file. Scrolling down through the file, you find several #define statements that define a token with a value. In this case, the value is the numerical signal and the token is the symbolic signal name. A more descriptive definition of the signal is included to the right between the /* and */ comment indicators. If you refer to the exit status of 133, it was determined that the signal for this exit status is 5. Using the sys/signal.h header file, it can be determined that signal 5 translates to a SIGSEGV signal that equates to an invalid memory reference. This information can then be used in searches to find a matching issue or supplied to Development to help with problem determination.

Refer to the following URL for a listing of all header files for UNIX-Type functions:

https://www.ibm.com/docs/api/v1/content/ssw_ibm_i_74/apis/unix13.htm