diff options
Diffstat (limited to 'man-pages-posix-2017/man1p/exit.1p')
| -rw-r--r-- | man-pages-posix-2017/man1p/exit.1p | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/man-pages-posix-2017/man1p/exit.1p b/man-pages-posix-2017/man1p/exit.1p new file mode 100644 index 0000000..d8d05cc --- /dev/null +++ b/man-pages-posix-2017/man1p/exit.1p @@ -0,0 +1,167 @@ +'\" et +.TH EXIT "1P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.\" +.SH NAME +exit +\(em cause the shell to exit +.SH SYNOPSIS +.LP +.nf +exit \fB[\fIn\fB]\fR +.fi +.SH DESCRIPTION +The +.IR exit +utility shall cause the shell to exit from its current execution +environment with the exit status specified by the unsigned decimal integer +.IR n . +If the current execution environment is a subshell environment, the +shell shall exit from the subshell environment with the specified exit +status and continue in the environment from which that subshell +environment was invoked; otherwise, the shell utility shall terminate +with the specified exit status. If +.IR n +is specified, but its value is not between 0 and 255 inclusively, the +exit status is undefined. +.P +A +.IR trap +on +.BR EXIT +shall be executed before the shell terminates, except when the +.IR exit +utility is invoked in that +.IR trap +itself, in which case the shell shall exit immediately. +.SH OPTIONS +None. +.SH OPERANDS +See the DESCRIPTION. +.SH STDIN +Not used. +.SH "INPUT FILES" +None. +.SH "ENVIRONMENT VARIABLES" +None. +.SH "ASYNCHRONOUS EVENTS" +Default. +.SH STDOUT +Not used. +.SH STDERR +The standard error shall be used only for diagnostic messages. +.SH "OUTPUT FILES" +None. +.SH "EXTENDED DESCRIPTION" +None. +.SH "EXIT STATUS" +The exit status shall be +.IR n , +if specified, except that the behavior is unspecified if +.IR n +is not an unsigned decimal integer or is greater than 255. Otherwise, +the value shall be the exit value of the last command executed, or +zero if no command was executed. When +.IR exit +is executed in a +.IR trap +action, the last command is considered to be the command that executed +immediately preceding the +.IR trap +action. +.SH "CONSEQUENCES OF ERRORS" +Default. +.LP +.IR "The following sections are informative." +.SH "APPLICATION USAGE" +None. +.SH EXAMPLES +Exit with a +.IR true +value: +.sp +.RS 4 +.nf + +exit 0 +.fi +.P +.RE +.P +Exit with a +.IR false +value: +.sp +.RS 4 +.nf + +exit 1 +.fi +.P +.RE +.P +Propagate error handling from within a subshell: +.sp +.RS 4 +.nf + +( + command1 || exit 1 + command2 || exit 1 + exec command3 +) > outputfile || exit 1 +echo "outputfile created successfully" +.fi +.P +.RE +.SH "RATIONALE" +As explained in other sections, certain exit status values have been +reserved for special uses and should be used by applications only for +those purposes: +.IP "\0126" 8 +A file to be executed was found, but it was not an executable utility. +.IP "\0127" 8 +A utility to be executed was not found. +.IP >128 8 +A command was interrupted by a signal. +.P +The behavior of +.IR exit +when given an invalid argument or unknown option is unspecified, +because of differing practices in the various historical +implementations. A value larger than 255 might be truncated by the +shell, and be unavailable even to a parent process that uses +\fIwaitid\fR() +to get the full exit value. It is recommended that implementations +that detect any usage error should cause a non-zero exit status (or, +if the shell is interactive and the error does not cause the shell to +abort, store a non-zero value in +.BR \(dq$?\(dq ), +but even this was not done historically in all shells. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "Section 2.14" ", " "Special Built-In Utilities" +.\" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1-2017, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, 2018 Edition, +Copyright (C) 2018 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +In the event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . +.PP +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |