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concat.c revision 1.1.1.2
      1 /* Concatenate variable number of strings.
      2    Copyright (C) 1991, 1994, 2001, 2011 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., 51 Franklin Street - Fifth Floor,
     19 Boston, MA 02110-1301, USA.  */
     20 
     21 
     22 /*
     23 
     24 @deftypefn Extension char* concat (const char *@var{s1}, const char *@var{s2}, @
     25   @dots{}, @code{NULL})
     26 
     27 Concatenate zero or more of strings and return the result in freshly
     28 @code{xmalloc}ed memory.  Returns @code{NULL} if insufficient memory is
     29 available.  The argument list is terminated by the first @code{NULL}
     30 pointer encountered.  Pointers to empty strings are ignored.
     31 
     32 @end deftypefn
     33 
     34 NOTES
     35 
     36 	This function uses xmalloc() which is expected to be a front end
     37 	function to malloc() that deals with low memory situations.  In
     38 	typical use, if malloc() returns NULL then xmalloc() diverts to an
     39 	error handler routine which never returns, and thus xmalloc will
     40 	never return a NULL pointer.  If the client application wishes to
     41 	deal with low memory situations itself, it should supply an xmalloc
     42 	that just directly invokes malloc and blindly returns whatever
     43 	malloc returns.
     44 
     45 */
     46 
     47 
     48 #ifdef HAVE_CONFIG_H
     49 #include "config.h"
     50 #endif
     51 #include "ansidecl.h"
     52 #include "libiberty.h"
     53 #include <sys/types.h>		/* size_t */
     54 
     55 #include <stdarg.h>
     56 
     57 # if HAVE_STRING_H
     58 #  include <string.h>
     59 # else
     60 #  if HAVE_STRINGS_H
     61 #   include <strings.h>
     62 #  endif
     63 # endif
     64 
     65 #if HAVE_STDLIB_H
     66 #include <stdlib.h>
     67 #endif
     68 
     69 static inline unsigned long vconcat_length (const char *, va_list);
     70 static inline unsigned long
     71 vconcat_length (const char *first, va_list args)
     72 {
     73   unsigned long length = 0;
     74   const char *arg;
     75 
     76   for (arg = first; arg ; arg = va_arg (args, const char *))
     77     length += strlen (arg);
     78 
     79   return length;
     80 }
     81 
     82 static inline char *
     83 vconcat_copy (char *dst, const char *first, va_list args)
     84 {
     85   char *end = dst;
     86   const char *arg;
     87 
     88   for (arg = first; arg ; arg = va_arg (args, const char *))
     89     {
     90       unsigned long length = strlen (arg);
     91       memcpy (end, arg, length);
     92       end += length;
     93     }
     94   *end = '\000';
     95 
     96   return dst;
     97 }
     98 
     99 /* @undocumented concat_length */
    100 
    101 unsigned long
    102 concat_length (const char *first, ...)
    103 {
    104   unsigned long length;
    105 
    106   VA_OPEN (args, first);
    107   VA_FIXEDARG (args, const char *, first);
    108   length = vconcat_length (first, args);
    109   VA_CLOSE (args);
    110 
    111   return length;
    112 }
    113 
    114 /* @undocumented concat_copy */
    115 
    116 char *
    117 concat_copy (char *dst, const char *first, ...)
    118 {
    119   char *save_dst;
    120 
    121   VA_OPEN (args, first);
    122   VA_FIXEDARG (args, char *, dst);
    123   VA_FIXEDARG (args, const char *, first);
    124   vconcat_copy (dst, first, args);
    125   save_dst = dst; /* With K&R C, dst goes out of scope here.  */
    126   VA_CLOSE (args);
    127 
    128   return save_dst;
    129 }
    130 
    131 #ifdef __cplusplus
    132 extern "C" {
    133 #endif /* __cplusplus */
    134 char *libiberty_concat_ptr;
    135 #ifdef __cplusplus
    136 }
    137 #endif /* __cplusplus */
    138 
    139 /* @undocumented concat_copy2 */
    140 
    141 char *
    142 concat_copy2 (const char *first, ...)
    143 {
    144   VA_OPEN (args, first);
    145   VA_FIXEDARG (args, const char *, first);
    146   vconcat_copy (libiberty_concat_ptr, first, args);
    147   VA_CLOSE (args);
    148 
    149   return libiberty_concat_ptr;
    150 }
    151 
    152 char *
    153 concat (const char *first, ...)
    154 {
    155   char *newstr;
    156 
    157   /* First compute the size of the result and get sufficient memory.  */
    158   VA_OPEN (args, first);
    159   VA_FIXEDARG (args, const char *, first);
    160   newstr = XNEWVEC (char, vconcat_length (first, args) + 1);
    161   VA_CLOSE (args);
    162 
    163   /* Now copy the individual pieces to the result string. */
    164   VA_OPEN (args, first);
    165   VA_FIXEDARG (args, const char *, first);
    166   vconcat_copy (newstr, first, args);
    167   VA_CLOSE (args);
    168 
    169   return newstr;
    170 }
    171 
    172 /*
    173 
    174 @deftypefn Extension char* reconcat (char *@var{optr}, const char *@var{s1}, @
    175   @dots{}, @code{NULL})
    176 
    177 Same as @code{concat}, except that if @var{optr} is not @code{NULL} it
    178 is freed after the string is created.  This is intended to be useful
    179 when you're extending an existing string or building up a string in a
    180 loop:
    181 
    182 @example
    183   str = reconcat (str, "pre-", str, NULL);
    184 @end example
    185 
    186 @end deftypefn
    187 
    188 */
    189 
    190 char *
    191 reconcat (char *optr, const char *first, ...)
    192 {
    193   char *newstr;
    194 
    195   /* First compute the size of the result and get sufficient memory.  */
    196   VA_OPEN (args, first);
    197   VA_FIXEDARG (args, char *, optr);
    198   VA_FIXEDARG (args, const char *, first);
    199   newstr = XNEWVEC (char, vconcat_length (first, args) + 1);
    200   VA_CLOSE (args);
    201 
    202   /* Now copy the individual pieces to the result string. */
    203   VA_OPEN (args, first);
    204   VA_FIXEDARG (args, char *, optr);
    205   VA_FIXEDARG (args, const char *, first);
    206   vconcat_copy (newstr, first, args);
    207   if (optr) /* Done before VA_CLOSE so optr stays in scope for K&R C.  */
    208     free (optr);
    209   VA_CLOSE (args);
    210 
    211   return newstr;
    212 }
    213 
    214 #ifdef MAIN
    215 #define NULLP (char *)0
    216 
    217 /* Simple little test driver. */
    218 
    219 #include <stdio.h>
    220 
    221 int
    222 main (void)
    223 {
    224   printf ("\"\" = \"%s\"\n", concat (NULLP));
    225   printf ("\"a\" = \"%s\"\n", concat ("a", NULLP));
    226   printf ("\"ab\" = \"%s\"\n", concat ("a", "b", NULLP));
    227   printf ("\"abc\" = \"%s\"\n", concat ("a", "b", "c", NULLP));
    228   printf ("\"abcd\" = \"%s\"\n", concat ("ab", "cd", NULLP));
    229   printf ("\"abcde\" = \"%s\"\n", concat ("ab", "c", "de", NULLP));
    230   printf ("\"abcdef\" = \"%s\"\n", concat ("", "a", "", "bcd", "ef", NULLP));
    231   return 0;
    232 }
    233 
    234 #endif
    235