| .\" (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de) |
| .\" |
| .\" 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| .\" manual page may be incorrect or out-of-date.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. |
| .\" License. |
| .\" Modified Sat Jul 24 19:53:02 1993 by Rik Faith (faith@cs.unc.edu) |
| .\" FIXME Many more values for 'name' are supported, some of which |
| .\" are documented under 'info confstr'. |
| .\" See <bits/confname.h> for the rest. |
| .\" These should all be added to this page. |
| .\" See also the SUSv3 specification of confstr() |
| .TH CONFSTR 3 1993-04-17 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| confstr \- get configuration dependent string variables |
| .SH SYNOPSIS |
| .nf |
| .B #define _POSIX_C_SOURCE 2 |
| or |
| .B #define _XOPEN_SOURCE |
| .nl |
| .B #include <unistd.h> |
| .sp |
| .BI "size_t confstr(int " "name" ", char *" buf ", size_t " len ); |
| .fi |
| .SH DESCRIPTION |
| .BR confstr () |
| gets the value of configuration-dependent string variables. |
| .PP |
| The |
| .I name |
| argument is the system variable to be queried. |
| The following variables are supported: |
| .TP |
| .BR _CS_GNU_LIBC_VERSION " (GNU C library only; since glibc 2.3.2)" |
| A string which identifies the GNU C library version on this system |
| (e.g, "glibc 2.3.4"). |
| .TP |
| .BR _CS_GNU_LIBPTHREAD_VERSION " (GNU C library only; since glibc 2.3.2)" |
| A string which identifies the POSIX implementation supplied by this |
| C library (e.g, "NPTL 2.3.4" or "linuxthreads-0.10"). |
| .TP |
| .B _CS_PATH |
| A value for the |
| .B PATH |
| variable which indicates where all the POSIX.2 standard utilities can |
| be found. |
| .PP |
| If |
| .I buf |
| is not NULL and |
| .I len |
| is not zero, |
| .BR confstr () |
| copies the value of the string to |
| .I buf |
| truncated to |
| .I len \- 1 |
| characters if necessary, with a null byte ('\\0') as terminator. |
| This can be detected by comparing the return value of |
| .BR confstr () |
| against |
| .IR len . |
| .PP |
| If |
| .I len |
| is zero and |
| .I buf |
| is NULL, |
| .BR confstr () |
| just returns the value as defined below. |
| .SH "RETURN VALUE" |
| If |
| .I name |
| does not correspond to a valid configuration variable, |
| .BR confstr () |
| returns 0. |
| .SH EXAMPLES |
| The following code fragment determines the path where to find |
| the POSIX.2 system utilities: |
| .br |
| .nf |
| .in 10 |
| |
| char *pathbuf; size_t n; |
| |
| n = confstr(_CS_PATH,NULL,(size_t)0); |
| if ((pathbuf = malloc(n)) == NULL) abort(); |
| confstr(_CS_PATH, pathbuf, n); |
| .SH ERRORS |
| If the value of |
| .I name |
| is invalid, |
| .I errno |
| is set to |
| .BR EINVAL . |
| .SH "CONFORMING TO" |
| proposed POSIX.2 |
| .SH BUGS |
| POSIX.2 is not yet an approved standard; the information in this |
| manpage is subject to change. |
| .SH "SEE ALSO" |
| .BR sh (1), |
| .BR exec (3), |
| .BR system (3) |