1/* Concatenate variable number of strings.
2 Copyright (C) 1991-2024 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., 51 Franklin Street - Fifth Floor,
19Boston, 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
27Concatenate zero or more of strings and return the result in freshly
28@code{xmalloc}ed memory. The argument list is terminated by the first
29@code{NULL} pointer encountered. Pointers to empty strings are ignored.
30
31@end deftypefn
32
33*/
34
35
36#ifdef HAVE_CONFIG_H
37#include "config.h"
38#endif
39#include "ansidecl.h"
40#include "libiberty.h"
41#include <sys/types.h> /* size_t */
42
43#include <stdarg.h>
44
45# if HAVE_STRING_H
46# include <string.h>
47# else
48# if HAVE_STRINGS_H
49# include <strings.h>
50# endif
51# endif
52
53#if HAVE_STDLIB_H
54#include <stdlib.h>
55#endif
56
57static inline unsigned long vconcat_length (const char *, va_list);
58static inline unsigned long
59vconcat_length (const char *first, va_list args)
60{
61 unsigned long length = 0;
62 const char *arg;
63
64 for (arg = first; arg ; arg = va_arg (args, const char *))
65 length += strlen (s: arg);
66
67 return length;
68}
69
70static inline char *
71vconcat_copy (char *dst, const char *first, va_list args)
72{
73 char *end = dst;
74 const char *arg;
75
76 for (arg = first; arg ; arg = va_arg (args, const char *))
77 {
78 unsigned long length = strlen (s: arg);
79 memcpy (dest: end, src: arg, n: length);
80 end += length;
81 }
82 *end = '\000';
83
84 return dst;
85}
86
87/* @undocumented concat_length */
88
89unsigned long
90concat_length (const char *first, ...)
91{
92 unsigned long length;
93 va_list args;
94
95 va_start (args, first);
96 length = vconcat_length (first, args);
97 va_end (args);
98
99 return length;
100}
101
102/* @undocumented concat_copy */
103
104char *
105concat_copy (char *dst, const char *first, ...)
106{
107 char *save_dst;
108 va_list args;
109
110 va_start (args, first);
111 vconcat_copy (dst, first, args);
112 save_dst = dst; /* With K&R C, dst goes out of scope here. */
113 va_end (args);
114
115 return save_dst;
116}
117
118#ifdef __cplusplus
119extern "C" {
120#endif /* __cplusplus */
121char *libiberty_concat_ptr;
122#ifdef __cplusplus
123}
124#endif /* __cplusplus */
125
126/* @undocumented concat_copy2 */
127
128char *
129concat_copy2 (const char *first, ...)
130{
131 va_list args;
132 va_start (args, first);
133 vconcat_copy (dst: libiberty_concat_ptr, first, args);
134 va_end (args);
135
136 return libiberty_concat_ptr;
137}
138
139char *
140concat (const char *first, ...)
141{
142 char *newstr;
143 va_list args;
144
145 /* First compute the size of the result and get sufficient memory. */
146 va_start (args, first);
147 newstr = XNEWVEC (char, vconcat_length (first, args) + 1);
148 va_end (args);
149
150 /* Now copy the individual pieces to the result string. */
151 va_start (args, first);
152 vconcat_copy (dst: newstr, first, args);
153 va_end (args);
154
155 return newstr;
156}
157
158/*
159
160@deftypefn Extension char* reconcat (char *@var{optr}, const char *@var{s1}, @
161 @dots{}, @code{NULL})
162
163Same as @code{concat}, except that if @var{optr} is not @code{NULL} it
164is freed after the string is created. This is intended to be useful
165when you're extending an existing string or building up a string in a
166loop:
167
168@example
169 str = reconcat (str, "pre-", str, NULL);
170@end example
171
172@end deftypefn
173
174*/
175
176char *
177reconcat (char *optr, const char *first, ...)
178{
179 char *newstr;
180 va_list args;
181
182 /* First compute the size of the result and get sufficient memory. */
183 va_start (args, first);
184 newstr = XNEWVEC (char, vconcat_length (first, args) + 1);
185 va_end (args);
186
187 /* Now copy the individual pieces to the result string. */
188 va_start (args, first);
189 vconcat_copy (dst: newstr, first, args);
190 if (optr) /* Done before VA_CLOSE so optr stays in scope for K&R C. */
191 free (ptr: optr);
192 va_end (args);
193
194 return newstr;
195}
196
197#ifdef MAIN
198#define NULLP (char *)0
199
200/* Simple little test driver. */
201
202#include <stdio.h>
203
204int
205main (void)
206{
207 printf ("\"\" = \"%s\"\n", concat (NULLP));
208 printf ("\"a\" = \"%s\"\n", concat ("a", NULLP));
209 printf ("\"ab\" = \"%s\"\n", concat ("a", "b", NULLP));
210 printf ("\"abc\" = \"%s\"\n", concat ("a", "b", "c", NULLP));
211 printf ("\"abcd\" = \"%s\"\n", concat ("ab", "cd", NULLP));
212 printf ("\"abcde\" = \"%s\"\n", concat ("ab", "c", "de", NULLP));
213 printf ("\"abcdef\" = \"%s\"\n", concat ("", "a", "", "bcd", "ef", NULLP));
214 return 0;
215}
216
217#endif
218

source code of libiberty/concat.c