/* argz.c -- argz implementation for non-glibc systems
 
    Copyright (C) 2004, 2006, 2007, 2008 Free Software Foundation, Inc.
    Written by Gary V. Vaughan, 2004
 
    NOTE: The canonical source of this file is maintained with the
    GNU Libtool package.  Report bugs to bug-libtool@gnu.org.
 
 GNU Libltdl 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 of the License, or (at your option) any later version.
 
 As a special exception to the GNU Lesser General Public License,
 if you distribute this file as part of a program or library that
 is built using GNU Libtool, you may include this file under the
 same distribution terms that you use for the rest of that program.
 
 GNU Libltdl 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 GNU Libltdl; see the file COPYING.LIB.  If not, a
 copy can be downloaded from  http://www.gnu.org/licenses/lgpl.html,
 or obtained by writing to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
 
 #if defined(LTDL) && defined LT_CONFIG_H
 #  include LT_CONFIG_H
 #else
 #  include <config.h>
 #endif
 
 #include <argz.h>
 
 #include <assert.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <errno.h>
 #include <string.h>
 
 #define EOS_CHAR '\0'
 
 error_t
 argz_append (char **pargz, size_t *pargz_len, const char *buf, size_t buf_len)
 {
   size_t argz_len;
   char  *argz;
 
   assert (pargz);
   assert (pargz_len);
   assert ((*pargz && *pargz_len) || (!*pargz && !*pargz_len));
 
   /* If nothing needs to be appended, no more work is required.  */
   if (buf_len == 0)
     return 0;
 
   /* Ensure there is enough room to append BUF_LEN.  */
   argz_len = *pargz_len + buf_len;
   argz = (char *) realloc (*pargz, argz_len);
   if (!argz)
     return ENOMEM;
 
   /* Copy characters from BUF after terminating '\0' in ARGZ.  */
   memcpy (argz + *pargz_len, buf, buf_len);
 
   /* Assign new values.  */
   *pargz = argz;
   *pargz_len = argz_len;
 
   return 0;
 }
 
 
 error_t
 argz_create_sep (const char *str, int delim, char **pargz, size_t *pargz_len)
 {
   size_t argz_len;
   char *argz = 0;
 
   assert (str);
   assert (pargz);
   assert (pargz_len);
 
   /* Make a copy of STR, but replacing each occurrence of
      DELIM with '\0'.  */
   argz_len = 1+ strlen (str);
   if (argz_len)
     {
       const char *p;
       char *q;
 
       argz = (char *) malloc (argz_len);
       if (!argz)
 	return ENOMEM;
 
       for (p = str, q = argz; *p != EOS_CHAR; ++p)
 	{
 	  if (*p == delim)
 	    {
 	      /* Ignore leading delimiters, and fold consecutive
 		 delimiters in STR into a single '\0' in ARGZ.  */
 	      if ((q > argz) && (q[-1] != EOS_CHAR))
 		*q++ = EOS_CHAR;
 	      else
 		--argz_len;
 	    }
 	  else
 	    *q++ = *p;
 	}
       /* Copy terminating EOS_CHAR.  */
       *q = *p;
     }
 
   /* If ARGZ_LEN has shrunk to nothing, release ARGZ's memory.  */
   if (!argz_len)
     argz = (free (argz), (char *) 0);
 
   /* Assign new values.  */
   *pargz = argz;
   *pargz_len = argz_len;
 
   return 0;
 }
 
 
 error_t
 argz_insert (char **pargz, size_t *pargz_len, char *before, const char *entry)
 {
   assert (pargz);
   assert (pargz_len);
   assert (entry && *entry);
 
   /* No BEFORE address indicates ENTRY should be inserted after the
      current last element.  */
   if (!before)
     return argz_append (pargz, pargz_len, entry, 1+ strlen (entry));
 
   /* This probably indicates a programmer error, but to preserve
      semantics, scan back to the start of an entry if BEFORE points
      into the middle of it.  */
   while ((before > *pargz) && (before[-1] != EOS_CHAR))
     --before;
 
   {
     size_t entry_len	= 1+ strlen (entry);
     size_t argz_len	= *pargz_len + entry_len;
     size_t offset	= before - *pargz;
     char   *argz	= (char *) realloc (*pargz, argz_len);
 
     if (!argz)
       return ENOMEM;
 
     /* Make BEFORE point to the equivalent offset in ARGZ that it
        used to have in *PARGZ incase realloc() moved the block.  */
     before = argz + offset;
 
     /* Move the ARGZ entries starting at BEFORE up into the new
        space at the end -- making room to copy ENTRY into the
        resulting gap.  */
     memmove (before + entry_len, before, *pargz_len - offset);
     memcpy  (before, entry, entry_len);
 
     /* Assign new values.  */
     *pargz = argz;
     *pargz_len = argz_len;
   }
 
   return 0;
 }
 
 
 char *
 argz_next (char *argz, size_t argz_len, const char *entry)
 {
   assert ((argz && argz_len) || (!argz && !argz_len));
 
   if (entry)
     {
       /* Either ARGZ/ARGZ_LEN is empty, or ENTRY points into an address
 	 within the ARGZ vector.  */
       assert ((!argz && !argz_len)
 	      || ((argz <= entry) && (entry < (argz + argz_len))));
 
       /* Move to the char immediately after the terminating
 	 '\0' of ENTRY.  */
       entry = 1+ strchr (entry, EOS_CHAR);
 
       /* Return either the new ENTRY, or else NULL if ARGZ is
 	 exhausted.  */
       return (entry >= argz + argz_len) ? 0 : (char *) entry;
     }
   else
     {
       /* This should probably be flagged as a programmer error,
 	 since starting an argz_next loop with the iterator set
 	 to ARGZ is safer.  To preserve semantics, handle the NULL
 	 case by returning the start of ARGZ (if any).  */
       if (argz_len > 0)
 	return argz;
       else
 	return 0;
     }
 }
 
 
 void
 argz_stringify (char *argz, size_t argz_len, int sep)
 {
   assert ((argz && argz_len) || (!argz && !argz_len));
 
   if (sep)
     {
       --argz_len;		/* don't stringify the terminating EOS */
       while (--argz_len > 0)
 	{
 	  if (argz[argz_len] == EOS_CHAR)
 	    argz[argz_len] = sep;
 	}
     }
 }