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Diffstat (limited to 'man3/setenv.3')
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diff --git a/man3/setenv.3 b/man3/setenv.3 new file mode 100644 index 000000000..3064e8afc --- /dev/null +++ b/man3/setenv.3 @@ -0,0 +1,86 @@ +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" +.\" 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 <mtk16@ext.canterbury.ac.nz> +.\" Changed unsetenv() prototype; added EINVAL error +.\" Noted non-standard behaviour of setenv() if name contains '=' +.\" +.TH SETENV 3 2004-05-09 "BSD" "Linux Programmer's Manual" +.SH NAME +setenv \- change or add an environment variable +.SH SYNOPSIS +.nf +.B #include <stdlib.h> +.sp +.BI "int setenv(const char *" name ", const char *" value ", int " overwrite ); +.sp +.BI "int unsetenv(const char *" name ); +.fi +.SH DESCRIPTION +The \fBsetenv()\fP function adds the variable \fIname\fP to the +environment with the value \fIvalue\fP, if \fIname\fP does not +already exist. If \fIname\fP does exist in the environment, then +its value is changed to \fIvalue\fP if \fIoverwrite\fP is non-zero; +if \fIoverwrite\fP is zero, then the value of \fIname\fP is not +changed. +.PP +The \fBunsetenv()\fP function deletes the variable \fIname\fP from +the environment. +.SH "RETURN VALUE" +The \fBsetenv()\fP function returns zero on success, or \-1 if there +was insufficient space in the environment. +The \fBunsetenv()\fP function returns zero on success, +or \-1 on error, with +.I errno +set to indicate the cause of the error. +.SH "ERRORS" +.TP +.B EINVAL +.I name +contained an '=' character. +.SH "CONFORMING TO" +BSD 4.3 +.SH "NOTES" +Prior to glibc 2.2.2, \fBunsetenv()\fP was prototyped +as returning \fIvoid\fP; more recent glibc versions follow the +SUSv3-compliant prototype shown in the SYNOPSIS. +.SH BUGS +SUSv3 specifies that if +.I name +contains an '=' character, then +.BR setenv () +should fail with the error +.BR EINVAL ; +however, glibc currently (v2.3.3) allows an '=' sign in +.IR name . +Portable applications should avoid this! +.SH "SEE ALSO" +.BR clearenv (3), +.BR getenv (3), +.BR putenv (3), +.BR environ (5) |