mirror of
https://github.com/postgres/postgres.git
synced 2025-07-20 05:03:10 +03:00
d3581d3161
collation/encoding to match English when reading controldata. This now matches the English variable setting used by pg_regress.c. Backpatch to 9.0.X.
58 lines
1.7 KiB
C
58 lines
1.7 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* unsetenv.c
|
|
* unsetenv() emulation for machines without it
|
|
*
|
|
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
*
|
|
* IDENTIFICATION
|
|
* $PostgreSQL: pgsql/src/port/unsetenv.c,v 1.11.6.1 2010/09/07 14:10:39 momjian Exp $
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
|
|
#include "c.h"
|
|
|
|
|
|
void
|
|
unsetenv(const char *name)
|
|
{
|
|
char *envstr;
|
|
|
|
if (getenv(name) == NULL)
|
|
return; /* no work */
|
|
|
|
/*
|
|
* The technique embodied here works if libc follows the Single Unix Spec
|
|
* and actually uses the storage passed to putenv() to hold the environ
|
|
* entry. When we clobber the entry in the second step we are ensuring
|
|
* that we zap the actual environ member. However, there are some libc
|
|
* implementations (notably recent BSDs) that do not obey SUS but copy the
|
|
* presented string. This method fails on such platforms. Hopefully all
|
|
* such platforms have unsetenv() and thus won't be using this hack.
|
|
* See: http://www.greenend.org.uk/rjk/2008/putenv.html
|
|
*
|
|
* Note that repeatedly setting and unsetting a var using this code will
|
|
* leak memory.
|
|
*/
|
|
|
|
envstr = (char *) malloc(strlen(name) + 2);
|
|
if (!envstr) /* not much we can do if no memory */
|
|
return;
|
|
|
|
/* Override the existing setting by forcibly defining the var */
|
|
sprintf(envstr, "%s=", name);
|
|
putenv(envstr);
|
|
|
|
/* Now we can clobber the variable definition this way: */
|
|
strcpy(envstr, "=");
|
|
|
|
/*
|
|
* This last putenv cleans up if we have multiple zero-length names as a
|
|
* result of unsetting multiple things.
|
|
*/
|
|
putenv(envstr);
|
|
}
|