/* Routines for dealing with '\0' separated environment vectors Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc. This file is part of the GNU C Library. Written by Miles Bader <miles@gnu.ai.mit.edu> The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <malloc.h> #include <string.h> #include "envz.h" /* The character separating names from values in an envz. */ #define SEP '=' /* Returns a pointer to the entry in ENVZ for NAME, or 0 if there is none. If NAME contains the separator character, only the portion before it is used in the comparison. */ char * envz_entry (const char *envz, size_t envz_len, const char *name) { while (envz_len) { const char *p = name; const char *entry = envz; /* Start of this entry. */ /* See how far NAME and ENTRY match. */ while (envz_len && *p == *envz && *p && *p != SEP) p++, envz++, envz_len--; if ((*envz == '\0' || *envz == SEP) && (*p == '\0' || *p == SEP)) /* Bingo! */ return (char *) entry; /* No match, skip to the next entry. */ while (envz_len && *envz) envz++, envz_len--; if (envz_len) envz++, envz_len--; /* skip '\0' */ } return 0; } /* Returns a pointer to the value portion of the entry in ENVZ for NAME, or 0 if there is none. */ char * envz_get (const char *envz, size_t envz_len, const char *name) { char *entry = envz_entry (envz, envz_len, name); if (entry) { while (*entry && *entry != SEP) entry++; if (*entry) entry++; else entry = 0; /* A null entry. */ } return entry; } /* Remove the entry for NAME from ENVZ & ENVZ_LEN, if any. */ void envz_remove (char **envz, size_t *envz_len, const char *name) { char *entry = envz_entry (*envz, *envz_len, name); if (entry) argz_delete (envz, envz_len, entry); } /* Adds an entry for NAME with value VALUE to ENVZ & ENVZ_LEN. If an entry with the same name already exists in ENVZ, it is removed. If VALUE is NULL, then the new entry will a special null one, for which envz_get will return NULL, although envz_entry will still return an entry; this is handy because when merging with another envz, the null entry can override an entry in the other one. Null entries can be removed with envz_strip (). */ error_t envz_add (char **envz, size_t *envz_len, const char *name, const char *value) { envz_remove (envz, envz_len, name); if (value) /* Add the new value, if there is one. */ { size_t name_len = strlen (name); size_t value_len = strlen (value); size_t old_envz_len = *envz_len; size_t new_envz_len = old_envz_len + name_len + 1 + value_len + 1; char *new_envz = realloc (*envz, new_envz_len); if (new_envz) { bcopy (name, new_envz + old_envz_len, name_len); new_envz[old_envz_len + name_len] = SEP; bcopy (value, new_envz + old_envz_len + name_len + 1, value_len); new_envz[new_envz_len - 1] = 0; *envz = new_envz; *envz_len = new_envz_len; return 0; } else return ENOMEM; } else /* Add a null entry. */ return __argz_add (envz, envz_len, name); } /* Adds each entry in ENVZ2 to ENVZ & ENVZ_LEN, as if with envz_add(). If OVERRIDE is true, then values in ENVZ2 will supersede those with the same name in ENV, otherwise not. */ error_t envz_merge (char **envz, size_t *envz_len, const char *envz2, size_t envz2_len, int override) { error_t err = 0; while (envz2_len && ! err) { char *old = envz_entry (*envz, *envz_len, envz2); size_t new_len = strlen (envz2) + 1; if (! old) err = __argz_append (envz, envz_len, envz2, new_len); else if (override) { argz_delete (envz, envz_len, old); err = __argz_append (envz, envz_len, envz2, new_len); } envz2 += new_len; envz2_len -= new_len; } return err; } /* Remove null entries. */ void envz_strip (char **envz, size_t *envz_len) { char *entry = *envz; size_t left = *envz_len; while (left) { size_t entry_len = strlen (entry) + 1; left -= entry_len; if (! index (entry, SEP)) /* Null entry. */ bcopy (entry, entry + entry_len, left); else entry += entry_len; } *envz_len = entry - *envz; }