Default Behavior: When the description of exit status 0 is ``Successful completion'', it means that exit status 0 shall indicate that all of the actions the utility is required to perform were completed successfully.

When jobs reports the termination status of a job, the shell shall remove its process ID from the list of those ``known in the current shell execution environment''; see [xref to 2.9.3.1].

If a write error occurs when jobs writes to standard output, some process IDs might have been removed from the list but not successfully reported.

0 Successful completion

0 The output specified in STDOUT was successfully written to standard output.

If jobs uses buffered writes to standard output, a write error could be detected when attempting to flush a buffer containing multiple reports of terminated jobs, resulting in some unreported jobs having their process IDs removed from the list of those known in the current shell execution environment (because they were removed when the report was added to the buffer).

0 Successful completion

1 The target was not up-to-date.

0 All specified targets were already up-to-date.

1 One or more targets were not up-to-date.

0 Successful completion

>0 An error occurred.

0 All specified targets were already up-to-date, or all commands executed to bring targets up-to-date either exited with status 0 or had a non-zero exit status that was specified (via the -i option, the special target .IGNORE, or a '-' command prefix) to be ignored.

>0 An error occurred, or at least one command executed to bring a target up-to-date exited with a non-zero exit status that was not specified to be ignored.