1 #ifndef _BABELTRACE_COMPAT_STDIO_H
2 #define _BABELTRACE_COMPAT_STDIO_H
3
4 /*
5 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25
26 #include <stdio.h>
27 #include <errno.h>
28 #include <assert.h>
29
30 #define BT_GETLINE_MINBUFLEN 64
31
32 static inline
_bt_getline_bufalloc(char ** lineptr,size_t * n,size_t linelen)33 char * _bt_getline_bufalloc(char **lineptr, size_t *n, size_t linelen)
34 {
35 size_t buflen = *n;
36 char *buf = *lineptr;
37
38 if (buflen >= linelen && buf != NULL) {
39 return buf;
40 }
41 if (buf == NULL) {
42 buflen = BT_GETLINE_MINBUFLEN;
43 } else {
44 buflen = buflen << 1;
45 if (buflen < BT_GETLINE_MINBUFLEN) {
46 buflen = BT_GETLINE_MINBUFLEN;
47 }
48 }
49 /* Check below not strictly needed, extra safety. */
50 if (buflen < linelen) {
51 buflen = linelen;
52 }
53 buf = realloc(buf, buflen);
54 if (!buf) {
55 errno = ENOMEM;
56 return NULL;
57 }
58 *n = buflen;
59 *lineptr = buf;
60 return buf;
61 }
62
63 /*
64 * Returns line length (including possible final \n, excluding final
65 * \0). On end of file, returns -1 with nonzero feof(stream) and errno
66 * set to 0. On error, returns -1 with errno set.
67 *
68 * This interface is similar to the getline(3) man page part of the
69 * Linux man-pages project, release 3.74. One major difference from the
70 * Open Group POSIX specification is that this implementation does not
71 * necessarily set the ferror() flag on error (because it is internal to
72 * libc).
73 */
74 static inline
bt_getline(char ** lineptr,size_t * n,FILE * stream)75 ssize_t bt_getline(char **lineptr, size_t *n, FILE *stream)
76 {
77 size_t linelen = 0;
78 char *buf;
79 int found_eof = 0;
80
81 if (lineptr == NULL || n == NULL) {
82 errno = EINVAL;
83 return -1;
84 }
85 for (;;) {
86 char c;
87 int ret;
88
89 ret = fgetc(stream);
90 if (ret == EOF) {
91 if (ferror(stream)) {
92 /* ferror() is set, errno set by fgetc(). */
93 return -1;
94 }
95 assert(feof(stream));
96 found_eof = 1;
97 break;
98 }
99 c = (char) ret;
100 if (linelen == SSIZE_MAX) {
101 errno = EOVERFLOW;
102 return -1;
103 }
104 buf = _bt_getline_bufalloc(lineptr, n, ++linelen);
105 if (!buf) {
106 return -1;
107 }
108 buf[linelen - 1] = c;
109 if (c == '\n') {
110 break;
111 }
112 }
113 if (!linelen && found_eof) {
114 /* feof() is set. */
115 errno = 0;
116 return -1;
117 }
118 buf = _bt_getline_bufalloc(lineptr, n, ++linelen);
119 if (!buf) {
120 return -1;
121 }
122 buf[linelen - 1] = '\0';
123 return linelen - 1; /* Count don't include final \0. */
124 }
125
126 #endif /* _BABELTRACE_COMPAT_STDIO_H */
127