concat.c revision 33965 
1/* Concatenate variable number of strings.
2   Copyright (C) 1991, 1994 Free Software Foundation, Inc.
3   Written by Fred Fish @ Cygnus Support
4
5This file is part of the libiberty library.
6Libiberty is free software; you can redistribute it and/or
7modify it under the terms of the GNU Library General Public
8License as published by the Free Software Foundation; either
9version 2 of the License, or (at your option) any later version.
10
11Libiberty is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14Library General Public License for more details.
15
16You should have received a copy of the GNU Library General Public
17License along with libiberty; see the file COPYING.LIB.  If
18not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA.  */
20
21
22/*
23
24NAME
25
26	concat -- concatenate a variable number of strings
27
28SYNOPSIS
29
30	#include <varargs.h>
31
32	char *concat (s1, s2, s3, ..., NULL)
33
34DESCRIPTION
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
43NOTES
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#ifdef __STDC__
66#include <stddef.h>
67extern size_t strlen (const char *s);
68#else
69extern int strlen ();
70#endif
71
72#define NULLP (char *)0
73
74/* VARARGS */
75#ifdef ANSI_PROTOTYPES
76char *
77concat (const char *first, ...)
78#else
79char *
80concat (va_alist)
81     va_dcl
82#endif
83{
84  register int 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
95#ifdef ANSI_PROTOTYPES
96  va_start (args, first);
97#else
98  va_start (args);
99  first = va_arg (args, const char *);
100#endif
101
102  if (first == NULLP)
103    length = 0;
104  else
105    {
106      length = strlen (first);
107      while ((arg = va_arg (args, const char *)) != NULLP)
108	{
109	  length += strlen (arg);
110	}
111    }
112  newstr = (char *) xmalloc (length + 1);
113  va_end (args);
114
115  /* Now copy the individual pieces to the result string. */
116
117  if (newstr != NULLP)
118    {
119#ifdef ANSI_PROTOTYPES
120      va_start (args, first);
121#else
122      va_start (args);
123      first = va_arg (args, const char *);
124#endif
125      end = newstr;
126      if (first != NULLP)
127	{
128	  arg = first;
129	  while (*arg)
130	    {
131	      *end++ = *arg++;
132	    }
133	  while ((arg = va_arg (args, const char *)) != NULLP)
134	    {
135	      while (*arg)
136		{
137		  *end++ = *arg++;
138		}
139	    }
140	}
141      *end = '\000';
142      va_end (args);
143    }
144
145  return (newstr);
146}
147
148#ifdef MAIN
149
150/* Simple little test driver. */
151
152#include <stdio.h>
153
154int
155main ()
156{
157  printf ("\"\" = \"%s\"\n", concat (NULLP));
158  printf ("\"a\" = \"%s\"\n", concat ("a", NULLP));
159  printf ("\"ab\" = \"%s\"\n", concat ("a", "b", NULLP));
160  printf ("\"abc\" = \"%s\"\n", concat ("a", "b", "c", NULLP));
161  printf ("\"abcd\" = \"%s\"\n", concat ("ab", "cd", NULLP));
162  printf ("\"abcde\" = \"%s\"\n", concat ("ab", "c", "de", NULLP));
163  printf ("\"abcdef\" = \"%s\"\n", concat ("", "a", "", "bcd", "ef", NULLP));
164  return 0;
165}
166
167#endif
168