/* xputenv.c: set an environment variable without return. */ /* Copyright 1993-98, 2008, 2009 Karl Berry. Copyright 2003-05 Olaf Weber. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, see . */ #include #include #ifdef WIN32 #include #else #if !HAVE_DECL_PUTENV extern int putenv (char* entry); #endif #endif /* not WIN32 */ /* * We have different arguments from the "standard" function. A separate * var and value tends to be much more practical. * * The standards for putenv are clear: put the passed string into the * environment, and if you alter that string, the environment changes. * Of course various implementations are broken in a number of ways, * which include making copies of the passed string, and more. */ void kpathsea_xputenv(kpathsea kpse, const char *var, const char *value) { char *cur_item; char *old_item; char *new_item; size_t var_lim; int cur_loc; /* kpse_debug2(KPSE_DEBUG_VARS, "kpse_putenv($%s,%s)", var, value); */ old_item = NULL; cur_item = concat3(var, "=", value); /* Include '=' in length. */ var_lim = strlen(var) + 1; /* Have we stored something for this value already? */ for (cur_loc = 0; cur_loc != kpse->saved_count; ++cur_loc) { if (strncmp(kpse->saved_env[cur_loc], cur_item, var_lim) == 0) { /* Get the old value. We need this is case another part * of the program didn't use us to change the environment. */ old_item = getenv(var); break; } } if (old_item && strcmp(old_item, cur_item+var_lim) == 0) { /* Set same value as is in environment, don't bother to set. */ free(cur_item); return; } else { /* We set a different value. */ if (putenv(cur_item) < 0) LIB_FATAL1("putenv(%s)", cur_item); /* Get the new string. */ new_item = getenv(var); if (new_item != cur_item+var_lim) { /* Our new string isn't used, don't keep it around. */ free(cur_item); return; } } /* If we get here, it means getenv() returned a reference to cur_item. So we save cur_item, and free the old string we also owned. */ if (cur_loc == kpse->saved_count) { /* No old string. */ kpse->saved_count++; XRETALLOC(kpse->saved_env, kpse->saved_count, char *); } else { /* We owned the old string. */ free(kpse->saved_env[cur_loc]); } kpse->saved_env[cur_loc] = cur_item; return; } /* A special case for setting a variable to a numeric value (specifically, KPATHSEA_DPI). We don't need to dynamically allocate and free the string for the number, since it's saved as part of the environment value. */ void kpathsea_xputenv_int (kpathsea kpse, const_string var_name, int num) { char str[MAX_INT_LENGTH]; sprintf (str, "%d", num); kpathsea_xputenv (kpse, var_name, str); } #if defined (KPSE_COMPAT_API) void xputenv (const char *var, const char *value) { kpathsea_xputenv (kpse_def, var, value); } void xputenv_int (const_string var_name, int num) { kpathsea_xputenv_int(kpse_def, var_name, num); } #endif