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