/* Functions for dealing with '\0' separated arg vectors.

   Copyright (C) 1995-1998, 2000-2002, 2006, 2008-2019 Free Software

   Foundation, Inc.

   This file is part of the GNU C Library.

   This program 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, or (at your option)

   any later version.

   This program 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 program; if not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

#include <argz.h>

#include <errno.h>

#include <stdlib.h>

#include <string.h>

/* Add BUF, of length BUF_LEN to the argz vector in ARGZ & ARGZ_LEN.  */

error_t

argz_append (char **argz, size_t *argz_len, const char *buf, size_t buf_len)

{

  size_t new_argz_len = *argz_len + buf_len;

  char *new_argz = realloc (*argz, new_argz_len);

  if (new_argz)

    {

      memcpy (new_argz + *argz_len, buf, buf_len);

      *argz = new_argz;

      *argz_len = new_argz_len;

      return 0;

    }

  else

    return ENOMEM;

}

/* Add STR to the argz vector in ARGZ & ARGZ_LEN.  This should be moved into

   argz.c in libshouldbelibc.  */

error_t

argz_add (char **argz, size_t *argz_len, const char *str)

{

  return argz_append (argz, argz_len, str, strlen (str) + 1);

}

error_t

argz_add_sep (char **argz, size_t *argz_len, const char *string, int delim)

{

  size_t nlen = strlen (string) + 1;

  if (nlen > 1)

    {

      const char *rp;

      char *wp;

      *argz = (char *) realloc (*argz, *argz_len + nlen);

      if (*argz == NULL)

        return ENOMEM;

      wp = *argz + *argz_len;

      rp = string;

      do

        if (*rp == delim)

          {

            if (wp > *argz && wp[-1] != '\0')

              *wp++ = '\0';

            else

              --nlen;

          }

        else

          *wp++ = *rp;

      while (*rp++ != '\0');

      *argz_len += nlen;

    }

  return 0;

}

error_t

argz_create_sep (const char *string, int delim, char **argz, size_t *len)

{

  size_t nlen = strlen (string) + 1;

  if (nlen > 1)

    {

      const char *rp;

      char *wp;

      *argz = (char *) malloc (nlen);

      if (*argz == NULL)

        return ENOMEM;

      rp = string;

      wp = *argz;

      do

        if (*rp == delim)

          {

            if (wp > *argz && wp[-1] != '\0')

              *wp++ = '\0';

            else

              --nlen;

          }

        else

          *wp++ = *rp;

      while (*rp++ != '\0');

      if (nlen == 0)

        {

          free (*argz);

          *argz = NULL;

          *len = 0;

        }

      *len = nlen;

    }

  else

    {

      *argz = NULL;

      *len = 0;

    }

  return 0;

}

/* Insert ENTRY into ARGZ & ARGZ_LEN before BEFORE, which should be an

   existing entry in ARGZ; if BEFORE is NULL, ENTRY is appended to the end.

   Since ARGZ's first entry is the same as ARGZ, argz_insert (ARGZ, ARGZ_LEN,

   ARGZ, ENTRY) will insert ENTRY at the beginning of ARGZ.  If BEFORE is not

   in ARGZ, EINVAL is returned, else if memory can't be allocated for the new

   ARGZ, ENOMEM is returned, else 0.  */

error_t

argz_insert (char **argz, size_t *argz_len, char *before, const char *entry)

{

  if (! before)

    return argz_add (argz, argz_len, entry);

  if (before < *argz || before >= *argz + *argz_len)

    return EINVAL;

  if (before > *argz)

    /* Make sure before is actually the beginning of an entry.  */

    while (before[-1])

      before--;

  {

    size_t after_before = *argz_len - (before - *argz);

    size_t entry_len = strlen  (entry) + 1;

    size_t new_argz_len = *argz_len + entry_len;

    char *new_argz = realloc (*argz, new_argz_len);

    if (new_argz)

      {

        before = new_argz + (before - *argz);

        memmove (before + entry_len, before, after_before);

        memmove (before, entry, entry_len);

        *argz = new_argz;

        *argz_len = new_argz_len;

        return 0;

      }

    else

      return ENOMEM;

  }

}

char *

argz_next (const char *argz, size_t argz_len, const char *entry)

{

  if (entry)

    {

      if (entry < argz + argz_len)

        entry = strchr (entry, '\0') + 1;

      return entry >= argz + argz_len ? NULL : (char *) entry;

    }

  else

    if (argz_len > 0)

      return (char *) argz;

    else

      return NULL;

}

/* Make '\0' separated arg vector ARGZ printable by converting all the '\0's

   except the last into the character SEP.  */

void

argz_stringify (char *argz, size_t len, int sep)

{

  if (len > 0)

    while (1)

      {

        size_t part_len = strnlen (argz, len);

        argz += part_len;

        len -= part_len;

        if (len-- <= 1)         /* includes final '\0' we want to stop at */

          break;

        *argz++ = sep;

      }

}

/* Returns the number of strings in ARGZ.  */

size_t

argz_count (const char *argz, size_t len)

{

  size_t count = 0;

  while (len > 0)

    {

      size_t part_len = strlen (argz);

      argz += part_len + 1;

      len -= part_len + 1;

      count++;

    }

  return count;

}

/* Puts pointers to each string in ARGZ, plus a terminating 0 element, into

   ARGV, which must be large enough to hold them all.  */

void

argz_extract (const char *argz, size_t len, char **argv)

{

  while (len > 0)

    {

      size_t part_len = strlen (argz);

      *argv++ = (char *) argz;

      argz += part_len + 1;

      len -= part_len + 1;

    }

  *argv = 0;

}

/* Make a '\0' separated arg vector from a unix argv vector, returning it in

   ARGZ, and the total length in LEN.  If a memory allocation error occurs,

   ENOMEM is returned, otherwise 0.  */

error_t

argz_create (char *const argv[], char **argz, size_t *len)

{

  int argc;

  size_t tlen = 0;

  char *const *ap;

  char *p;

  for (argc = 0; argv[argc] != NULL; ++argc)

    tlen += strlen (argv[argc]) + 1;

  if (tlen == 0)

    *argz = NULL;

  else

    {

      *argz = malloc (tlen);

      if (*argz == NULL)

        return ENOMEM;

      for (p = *argz, ap = argv; *ap; ++ap, ++p)

        p = stpcpy (p, *ap);

    }

  *len = tlen;

  return 0;

}

/* Delete ENTRY from ARGZ & ARGZ_LEN, if any.  */

void

argz_delete (char **argz, size_t *argz_len, char *entry)

{

  if (entry)

    /* Get rid of the old value for NAME.  */

    {

      size_t entry_len = strlen (entry) + 1;

      *argz_len -= entry_len;

      memmove (entry, entry + entry_len, *argz_len - (entry - *argz));

      if (*argz_len == 0)

        {

          free (*argz);

          *argz = 0;

        }

    }

}

/* Append BUF, of length BUF_LEN to *TO, of length *TO_LEN, reallocating and

   updating *TO & *TO_LEN appropriately.  If an allocation error occurs,

   *TO's old value is freed, and *TO is set to 0.  */

static void

str_append (char **to, size_t *to_len, const char *buf, const size_t buf_len)

{

  size_t new_len = *to_len + buf_len;

  char *new_to = realloc (*to, new_len + 1);

  if (new_to)

    {

      *((char *) mempcpy (new_to + *to_len, buf, buf_len)) = '\0';

      *to = new_to;

      *to_len = new_len;

    }

  else

    {

      free (*to);

      *to = 0;

    }

}

/* Replace any occurrences of the string STR in ARGZ with WITH, reallocating

   ARGZ as necessary.  If REPLACE_COUNT is non-zero, *REPLACE_COUNT will be

   incremented by number of replacements performed.  */

error_t

argz_replace (char **argz, size_t *argz_len, const char *str, const char *with,

                unsigned *replace_count)

{

  error_t err = 0;

  if (str && *str)

    {

      char *arg = 0;

      char *src = *argz;

      size_t src_len = *argz_len;

      char *dst = 0;

      size_t dst_len = 0;

      int delayed_copy = 1;     /* True while we've avoided copying anything.  */

      size_t str_len = strlen (str), with_len = strlen (with);

      while (!err && (arg = argz_next (src, src_len, arg)))

        {

          char *match = strstr (arg, str);

          if (match)

            {

              char *from = match + str_len;

              size_t to_len = match - arg;

              char *to = strndup (arg, to_len);

              while (to && from)

                {

                  str_append (&to, &to_len, with, with_len);

                  if (to)

                    {

                      match = strstr (from, str);

                      if (match)

                        {

                          str_append (&to, &to_len, from, match - from);

                          from = match + str_len;

                        }

                      else

                        {

                          str_append (&to, &to_len, from, strlen (from));

                          from = 0;

                        }

                    }

                }

              if (to)

                {

                  if (delayed_copy)

                    /* We avoided copying SRC to DST until we found a match;

                       now that we've done so, copy everything from the start

                       of SRC.  */

                    {

                      if (arg > src)

                        err = argz_append (&dst, &dst_len, src, (arg - src));

                      delayed_copy = 0;

                    }

                  if (! err)

                    err = argz_add (&dst, &dst_len, to);

                  free (to);

                }

              else

                err = ENOMEM;

              if (replace_count)

                (*replace_count)++;

            }

          else if (! delayed_copy)

            err = argz_add (&dst, &dst_len, arg);

        }

      if (! err)

        {

          if (! delayed_copy)

            /* We never found any instances of str.  */

            {

              free (src);

              *argz = dst;

              *argz_len = dst_len;

            }

        }

      else if (dst_len > 0)

        free (dst);

    }

  return err;

}