libite 2.6.1
popenf.c
1/* Formatted popen()
2 *
3 * Copyright (c) 2023 Tobias Waldekranz <tobias@waldekranz.com>
4 * Copyright (c) 2023 Joachim Wiberg <troglobit@gmail.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25#include <errno.h>
26#include <stdio.h>
27#include <stdarg.h>
28#include <stdlib.h>
29
42FILE *popenf(const char *type, const char *fmt, ...)
43{
44 va_list ap;
45 char *cmd;
46 int len;
47
48 va_start(ap, fmt);
49 len = vsnprintf(NULL, 0, fmt, ap);
50 va_end(ap);
51
52 cmd = alloca(len + 1);
53 if (!cmd) {
54 errno = ENOMEM;
55 return NULL;
56 }
57
58 va_start(ap, fmt);
59 vsnprintf(cmd, len + 1, fmt, ap);
60 va_end(ap);
61
62 return popen(cmd, type);
63}