/* * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands. * See the copyright notice in the ACK home directory, in the file "Copyright". */ /* $Id$ */ #include #include extern char* _findenv(const char* name, int* offset); extern char** environ; /* * setenv(name,value,rewrite) * Set the value of the environmental variable "name" to be * "value". If rewrite is set, replace any current value. */ int setenv(register const char* name, register const char* value, int rewrite) { static int alloced = 0; /* if allocated space before */ register char* C; int l_value, offset; if (*value == '=') /* no `=' in value */ ++value; l_value = strlen(value); if ((C = _findenv(name, &offset))) { /* find if already exists */ if (!rewrite) return (0); if (strlen(C) >= l_value) { /* old larger; copy over */ while (*C++ = *value++) ; return (0); } } else { /* create new slot */ register int cnt = 0; register char** P; if (environ) for (P = environ; *P; ++P, ++cnt) ; if (alloced) { /* just increase size */ environ = (char**)realloc((char*)environ, (unsigned)(sizeof(char*) * (cnt + 2))); if (!environ) return (-1); } else { /* get new space */ alloced = 1; /* copy old entries into it */ P = (char**)malloc((unsigned)(sizeof(char*) * (cnt + 2))); if (!P) return (-1); if (environ) bcopy(environ, P, cnt * sizeof(char*)); environ = P; } environ[cnt + 1] = NULL; offset = cnt; } for (C = (char*) name; *C && *C != '='; ++C) ; /* no `=' in name */ if (!(environ[offset] = /* name + `=' + value */ malloc((unsigned)((int)(C - name) + l_value + 2)))) return (-1); for (C = environ[offset]; (*C = *name++) && *C != '='; ++C) ; for (*C++ = '='; *C++ = *value++;) ; return (0); } /* * unsetenv(name) -- * Delete environmental variable "name". */ int unsetenv(const char* name) { register char** P; int offset; while (_findenv(name, &offset)) /* if set multiple times */ for (P = &environ[offset];; ++P) if (!(*P = *(P + 1))) break; return 0; }