libiberty/concat.c

   1 /* Concatenate variable number of strings.
   2    Copyright (C) 1991, 1994, 2001 Free Software Foundation, Inc.
   3    Written by Fred Fish @ Cygnus Support
   4
   5 This file is part of the libiberty library.
   6 Libiberty is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU Library General Public
   8 License as published by the Free Software Foundation; either
   9 version 2 of the License, or (at your option) any later version.
  10
  11 Libiberty is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 Library General Public License for more details.
  15
  16 You should have received a copy of the GNU Library General Public
  17 License along with libiberty; see the file COPYING.LIB.  If
  18 not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21
  22 /*
  23
  24 NAME
  25
  26         concat -- concatenate a variable number of strings
  27
  28 SYNOPSIS
  29
  30         #include <varargs.h>
  31
  32         char *concat (s1, s2, s3, ..., NULL)
  33
  34 DESCRIPTION
  35
  36         Concatenate a variable number of strings and return the result
  37         in freshly malloc'd memory.
  38
  39         Returns NULL if insufficient memory is available.  The argument
  40         list is terminated by the first NULL pointer encountered.  Pointers
  41         to empty strings are ignored.
  42
  43 NOTES
  44
  45         This function uses xmalloc() which is expected to be a front end
  46         function to malloc() that deals with low memory situations.  In
  47         typical use, if malloc() returns NULL then xmalloc() diverts to an
  48         error handler routine which never returns, and thus xmalloc will
  49         never return a NULL pointer.  If the client application wishes to
  50         deal with low memory situations itself, it should supply an xmalloc
  51         that just directly invokes malloc and blindly returns whatever
  52         malloc returns.
  53 */
  54
  55
  56 #ifdef HAVE_CONFIG_H
  57 #include "config.h"
  58 #endif
  59 #include "ansidecl.h"
  60 #include "libiberty.h"
  61 #include <sys/types.h>          /* size_t */
  62
  63 #ifdef ANSI_PROTOTYPES
  64 #include <stdarg.h>
  65 #else
  66 #include <varargs.h>
  67 #endif
  68
  69 # if HAVE_STRING_H
  70 #  include <string.h>
  71 # else
  72 #  if HAVE_STRINGS_H
  73 #   include <strings.h>
  74 #  endif
  75 # endif
  76
  77 /* VARARGS */
  78 #ifdef ANSI_PROTOTYPES
  79 char *
  80 concat (const char *first, ...)
  81 #else
  82 char *
  83 concat (va_alist)
  84      va_dcl
  85 #endif
  86 {
  87   register size_t length;
  88   register char *newstr;
  89   register char *end;
  90   register const char *arg;
  91   va_list args;
  92 #ifndef ANSI_PROTOTYPES
  93   const char *first;
  94 #endif
  95
  96   /* First compute the size of the result and get sufficient memory.  */
  97 #ifdef ANSI_PROTOTYPES
  98   va_start (args, first);
  99 #else
 100   va_start (args);
 101   first = va_arg (args, const char *);
 102 #endif
 103
 104   length = 0;
 105   for (arg = first; arg ; arg = va_arg (args, const char *))
 106     length += strlen (arg);
 107
 108   va_end (args);
 109
 110   newstr = (char *) xmalloc (length + 1);
 111
 112   /* Now copy the individual pieces to the result string. */
 113 #ifdef ANSI_PROTOTYPES
 114   va_start (args, first);
 115 #else
 116   va_start (args);
 117   first = va_arg (args, const char *);
 118 #endif
 119
 120   end = newstr;
 121   for (arg = first; arg ; arg = va_arg (args, const char *))
 122     {
 123       length = strlen (arg);
 124       memcpy (end, arg, length);
 125       end += length;
 126     }
 127   *end = '\000';
 128   va_end (args);
 129
 130   return newstr;
 131 }
 132
 133 #ifdef MAIN
 134 #define NULLP (char *)0
 135
 136 /* Simple little test driver. */
 137
 138 #include <stdio.h>
 139
 140 int
 141 main ()
 142 {
 143   printf ("\"\" = \"%s\"\n", concat (NULLP));
 144   printf ("\"a\" = \"%s\"\n", concat ("a", NULLP));
 145   printf ("\"ab\" = \"%s\"\n", concat ("a", "b", NULLP));
 146   printf ("\"abc\" = \"%s\"\n", concat ("a", "b", "c", NULLP));
 147   printf ("\"abcd\" = \"%s\"\n", concat ("ab", "cd", NULLP));
 148   printf ("\"abcde\" = \"%s\"\n", concat ("ab", "c", "de", NULLP));
 149   printf ("\"abcdef\" = \"%s\"\n", concat ("", "a", "", "bcd", "ef", NULLP));
 150   return 0;
 151 }
 152
 153 #endif