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diff --git a/man1p/nohup.1p b/man1p/nohup.1p new file mode 100644 index 000000000..893218fd9 --- /dev/null +++ b/man1p/nohup.1p @@ -0,0 +1,215 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "NOHUP" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" nohup +.SH NAME +nohup \- invoke a utility immune to hangups +.SH SYNOPSIS +.LP +\fBnohup\fP \fIutility\fP \fB[\fP\fIargument\fP\fB...\fP\fB]\fP +.SH DESCRIPTION +.LP +The \fInohup\fP utility shall invoke the utility named by the \fIutility\fP +operand with arguments supplied as the +\fIargument\fP operands. At the time the named \fIutility\fP is invoked, +the SIGHUP signal shall be set to be ignored. +.LP +If the standard output is a terminal, all output written by the named +\fIutility\fP to its standard output shall be appended to +the end of the file \fBnohup.out\fP in the current directory. If \fBnohup.out\fP +cannot be created or opened for appending, the +output shall be appended to the end of the file \fBnohup.out\fP in +the directory specified by the \fIHOME\fP environment +variable. If neither file can be created or opened for appending, +\fIutility\fP shall not be invoked. If a file is created, the +file's permission bits shall be set to S_IRUSR | S_IWUSR. +.LP +If the standard error is a terminal, all output written by the named +\fIutility\fP to its standard error shall be redirected to +the same file descriptor as the standard output. +.SH OPTIONS +.LP +None. +.SH OPERANDS +.LP +The following operands shall be supported: +.TP 7 +\fIutility\fP +The name of a utility that is to be invoked. If the \fIutility\fP +operand names any of the special built-in utilities in \fISpecial +Built-In Utilities\fP , the results are undefined. +.TP 7 +\fIargument\fP +Any string to be supplied as an argument when invoking the utility +named by the \fIutility\fP operand. +.sp +.SH STDIN +.LP +Not used. +.SH INPUT FILES +.LP +None. +.SH ENVIRONMENT VARIABLES +.LP +The following environment variables shall affect the execution of +\fInohup\fP: +.TP 7 +\fIHOME\fP +Determine the pathname of the user's home directory: if the output +file \fBnohup.out\fP cannot be created in the current +directory, the \fInohup\fP utility shall use the directory named by +\fIHOME\fP to create the file. +.TP 7 +\fILANG\fP +Provide a default value for the internationalization variables that +are unset or null. (See the Base Definitions volume of +IEEE\ Std\ 1003.1-2001, Section 8.2, Internationalization Variables +for +the precedence of internationalization variables used to determine +the values of locale categories.) +.TP 7 +\fILC_ALL\fP +If set to a non-empty string value, override the values of all the +other internationalization variables. +.TP 7 +\fILC_CTYPE\fP +Determine the locale for the interpretation of sequences of bytes +of text data as characters (for example, single-byte as +opposed to multi-byte characters in arguments). +.TP 7 +\fILC_MESSAGES\fP +Determine the locale that should be used to affect the format and +contents of diagnostic messages written to standard +error. +.TP 7 +\fINLSPATH\fP +Determine the location of message catalogs for the processing of \fILC_MESSAGES +\&.\fP +.TP 7 +\fIPATH\fP +Determine the search path that is used to locate the utility to be +invoked. See the Base Definitions volume of +IEEE\ Std\ 1003.1-2001, Chapter 8, Environment Variables. +.sp +.SH ASYNCHRONOUS EVENTS +.LP +The \fInohup\fP utility shall take the standard action for all signals +except that SIGHUP shall be ignored. +.SH STDOUT +.LP +If the standard output is not a terminal, the standard output of \fInohup\fP +shall be the standard output generated by the +execution of the \fIutility\fP specified by the operands. Otherwise, +nothing shall be written to the standard output. +.SH STDERR +.LP +If the standard output is a terminal, a message shall be written to +the standard error, indicating the name of the file to which +the output is being appended. The name of the file shall be either +\fBnohup.out\fP or \fB$HOME/nohup.out\fP. +.SH OUTPUT FILES +.LP +If the standard output is a terminal, all output written by the named +\fIutility\fP to the standard output and standard error +is appended to the file \fBnohup.out\fP, which is created if it does +not already exist. +.SH EXTENDED DESCRIPTION +.LP +None. +.SH EXIT STATUS +.LP +The following exit values shall be returned: +.TP 7 +126 +The utility specified by \fIutility\fP was found but could not be +invoked. +.TP 7 +127 +An error occurred in the \fInohup\fP utility or the utility specified +by \fIutility\fP could not be found. +.sp +.LP +Otherwise, the exit status of \fInohup\fP shall be that of the utility +specified by the \fIutility\fP operand. +.SH CONSEQUENCES OF ERRORS +.LP +Default. +.LP +\fIThe following sections are informative.\fP +.SH APPLICATION USAGE +.LP +The \fIcommand\fP, \fIenv\fP, \fInice\fP, \fInohup\fP, \fItime\fP, +and \fIxargs\fP utilities have been specified to use exit code 127 +if an error occurs so that +applications can distinguish "failure to find a utility" from "invoked +utility exited with an error indication". The value 127 +was chosen because it is not commonly used for other meanings; most +utilities use small values for "normal error conditions" and +the values above 128 can be confused with termination due to receipt +of a signal. The value 126 was chosen in a similar manner to +indicate that the utility could be found, but not invoked. Some scripts +produce meaningful error messages differentiating the 126 +and 127 cases. The distinction between exit codes 126 and 127 is based +on KornShell practice that uses 127 when all attempts to +\fIexec\fP the utility fail with [ENOENT], and uses 126 when any attempt +to \fIexec\fP the utility fails for any other +reason. +.SH EXAMPLES +.LP +It is frequently desirable to apply \fInohup\fP to pipelines or lists +of commands. This can be done by placing pipelines and +command lists in a single file; this file can then be invoked as a +utility, and the \fInohup\fP applies to everything in the +file. +.LP +Alternatively, the following command can be used to apply \fInohup\fP +to a complex command: +.sp +.RS +.nf + +\fBnohup sh -c '\fP\fIcomplex-command-line\fP\fB' +\fP +.fi +.RE +.SH RATIONALE +.LP +The 4.3 BSD version ignores SIGTERM and SIGHUP, and if \fB./nohup.out\fP +cannot be used, it fails instead of trying to use +\fB$HOME/nohup.out\fP. +.LP +The \fIcsh\fP utility has a built-in version of \fInohup\fP that acts +differently from the \fInohup\fP defined in this volume +of IEEE\ Std\ 1003.1-2001. +.LP +The term \fIutility\fP is used, rather than \fIcommand\fP, to highlight +the fact that shell compound commands, pipelines, +special built-ins, and so on, cannot be used directly. However, \fIutility\fP +includes user application programs and shell +scripts, not just the standard utilities. +.LP +Historical versions of the \fInohup\fP utility use default file creation +semantics. Some more recent versions use the +permissions specified here as an added security precaution. +.LP +Some historical implementations ignore SIGQUIT in addition to SIGHUP; +others ignore SIGTERM. An early proposal allowed, but did +not require, SIGQUIT to be ignored. Several reviewers objected that +\fInohup\fP should only modify the handling of SIGHUP as +required by this volume of IEEE\ Std\ 1003.1-2001. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIShell Command Language\fP , \fIsh\fP , the System Interfaces +volume of IEEE\ Std\ 1003.1-2001, \fIsignal\fP() +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 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 . |