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 #include "ansidecl.h"
  57 #include "libiberty.h"
  58
  59 #ifdef ANSI_PROTOTYPES
  60 #include <stdarg.h>
  61 #else
  62 #include <varargs.h>
  63 #endif
  64
  65 # if HAVE_STRING_H
  66 #  include <string.h>
  67 # else
  68 #  if HAVE_STRINGS_H
  69 #   include <strings.h>
  70 #  endif
  71 # endif
  72
  73 /* VARARGS */
  74 #ifdef ANSI_PROTOTYPES
  75 char *
  76 concat (const char *first, ...)
  77 #else
  78 char *
  79 concat (va_alist)
  80      va_dcl
  81 #endif
  82 {
  83   register size_t length;
  84   register char *newstr;
  85   register char *end;
  86   register const char *arg;
  87   va_list args;
  88 #ifndef ANSI_PROTOTYPES
  89   const char *first;
  90 #endif
  91
  92   /* First compute the size of the result and get sufficient memory.  */
  93 #ifdef ANSI_PROTOTYPES
  94   va_start (args, first);
  95 #else
  96   va_start (args);
  97   first = va_arg (args, const char *);
  98 #endif
  99
 100   length = 0;
 101   for (arg = first; arg ; arg = va_arg (args, const char *))
 102     length += strlen (arg);
 103
 104   va_end (args);
 105
 106   newstr = (char *) xmalloc (length + 1);
 107
 108   /* Now copy the individual pieces to the result string. */
 109 #ifdef ANSI_PROTOTYPES
 110   va_start (args, first);
 111 #else
 112   va_start (args);
 113   first = va_arg (args, const char *);
 114 #endif
 115
 116   end = newstr;
 117   for (arg = first; arg ; arg = va_arg (args, const char *))
 118     {
 119       length = strlen (arg);
 120       memcpy (end, arg, length);
 121       end += length;
 122     }
 123   *end = '\000';
 124   va_end (args);
 125
 126   return newstr;
 127 }
 128
 129 #ifdef MAIN
 130 #define NULLP (char *)0
 131
 132 /* Simple little test driver. */
 133
 134 #include <stdio.h>
 135
 136 int
 137 main ()
 138 {
 139   printf ("\"\" = \"%s\"\n", concat (NULLP));
 140   printf ("\"a\" = \"%s\"\n", concat ("a", NULLP));
 141   printf ("\"ab\" = \"%s\"\n", concat ("a", "b", NULLP));
 142   printf ("\"abc\" = \"%s\"\n", concat ("a", "b", "c", NULLP));
 143   printf ("\"abcd\" = \"%s\"\n", concat ("ab", "cd", NULLP));
 144   printf ("\"abcde\" = \"%s\"\n", concat ("ab", "c", "de", NULLP));
 145   printf ("\"abcdef\" = \"%s\"\n", concat ("", "a", "", "bcd", "ef", NULLP));
 146   return 0;
 147 }
 148
 149 #endif