From 3d08cd331c1adcf0d917392f7e527b3f00511748 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 24 May 2024 06:52:22 +0200 Subject: Merging upstream version 6.8. Signed-off-by: Daniel Baumann --- man/man3/setenv.3 | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 man/man3/setenv.3 (limited to 'man/man3/setenv.3') diff --git a/man/man3/setenv.3 b/man/man3/setenv.3 new file mode 100644 index 0000000..d6f9683 --- /dev/null +++ b/man/man3/setenv.3 @@ -0,0 +1,150 @@ +'\" t +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" and Copyright (C) 2004, 2007 Michael Kerrisk +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified Sat Jul 24 18:20:58 1993 by Rik Faith (faith@cs.unc.edu) +.\" Modified Fri Feb 14 21:47:50 1997 by Andries Brouwer (aeb@cwi.nl) +.\" Modified 9 Jun 2004, Michael Kerrisk +.\" Changed unsetenv() prototype; added EINVAL error +.\" Noted nonstandard behavior of setenv() if name contains '=' +.\" 2005-08-12, mtk, glibc 2.3.4 fixed the "name contains '='" bug +.\" +.TH setenv 3 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +setenv \- change or add an environment variable +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include +.P +.BI "int setenv(const char *" name ", const char *" value ", int " overwrite ); +.BI "int unsetenv(const char *" name ); +.fi +.P +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.P +.BR setenv (), +.BR unsetenv (): +.nf + _POSIX_C_SOURCE >= 200112L + || /* glibc <= 2.19: */ _BSD_SOURCE +.fi +.SH DESCRIPTION +The +.BR setenv () +function adds the variable +.I name +to the +environment with the value +.IR value , +if +.I name +does not +already exist. +If +.I name +does exist in the environment, then +its value is changed to +.I value +if +.I overwrite +is nonzero; +if +.I overwrite +is zero, then the value of +.I name +is not changed (and +.BR setenv () +returns a success status). +This function makes copies of the strings pointed to by +.I name +and +.I value +(by contrast with +.BR putenv (3)). +.P +The +.BR unsetenv () +function deletes the variable +.I name +from +the environment. +If +.I name +does not exist in the environment, +then the function succeeds, and the environment is unchanged. +.SH RETURN VALUE +.BR setenv () +and +.BR unsetenv () +functions return zero on success, +or \-1 on error, with +.I errno +set to indicate the error. +.SH ERRORS +.TP +.B EINVAL +.I name +is NULL, points to a string of length 0, +or contains an \[aq]=\[aq] character. +.TP +.B ENOMEM +Insufficient memory to add a new variable to the environment. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR setenv (), +.BR unsetenv () +T} Thread safety MT-Unsafe const:env +.TE +.SH STANDARDS +POSIX.1-2008. +.SH HISTORY +POSIX.1-2001, 4.3BSD. +.P +Prior to glibc 2.2.2, +.BR unsetenv () +was prototyped +as returning +.IR void ; +more recent glibc versions follow the +POSIX.1-compliant prototype shown in the SYNOPSIS. +.SH CAVEATS +POSIX.1 does not require +.BR setenv () +or +.BR unsetenv () +to be reentrant. +.SH BUGS +POSIX.1 specifies that if +.I name +contains an \[aq]=\[aq] character, then +.BR setenv () +should fail with the error +.BR EINVAL ; +however, versions of glibc before glibc 2.3.4 allowed an \[aq]=\[aq] sign in +.IR name . +.SH SEE ALSO +.BR clearenv (3), +.BR getenv (3), +.BR putenv (3), +.BR environ (7) -- cgit v1.2.3