diff options
Diffstat (limited to 'Doc/help/wait')
| -rw-r--r-- | Doc/help/wait | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/Doc/help/wait b/Doc/help/wait index 876a9669f..753127278 100644 --- a/Doc/help/wait +++ b/Doc/help/wait @@ -1,25 +1,25 @@ wait [ job ... ] - Wait for the specified jobs or processes. If job is not given - then all currently active child processes are waited for. Each + Wait for the specified jobs or processes. If job is not given + then all currently active child processes are waited for. Each job can be either a job specification or the process ID of a job - in the job table. The exit status from this command is that of + in the job table. The exit status from this command is that of the job waited for. If job represents an unknown job or process - ID, a warning is printed (unless the POSIX_BUILTINS option is + ID, a warning is printed (unless the POSIX_BUILTINS option is set) and the exit status is 127. - It is possible to wait for recent processes (specified by + It is possible to wait for recent processes (specified by process ID, not by job) that were running in the background even - if the process has exited. Typically the process ID will be - recorded by capturing the value of the variable $! immediately - after the process has been started. There is a limit on the - number of process IDs remembered by the shell; this is given by + if the process has exited. Typically the process ID will be + recorded by capturing the value of the variable $! immediately + after the process has been started. There is a limit on the + number of process IDs remembered by the shell; this is given by the value of the system configuration parameter CHILD_MAX. When - this limit is reached, older process IDs are discarded, least + this limit is reached, older process IDs are discarded, least recently started processes first. - Note there is no protection against the process ID wrapping, - i.e. if the wait is not executed soon enough there is a chance - the process waited for is the wrong one. A conflict implies + Note there is no protection against the process ID wrapping, + i.e. if the wait is not executed soon enough there is a chance + the process waited for is the wrong one. A conflict implies both process IDs have been generated by the shell, as other pro- cesses are not recorded, and that the user is potentially inter- ested in both, so this problem is intrinsic to process IDs. |