| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | */ |
| 6 | |
| 7 | #ifndef BABELTRACE_COMPAT_STDIO_H |
| 8 | #define BABELTRACE_COMPAT_STDIO_H |
| 9 | |
| 10 | #include <stdio.h> |
| 11 | #include <errno.h> |
| 12 | #include <stdlib.h> |
| 13 | #include <limits.h> |
| 14 | #include "common/assert.h" |
| 15 | |
| 16 | #define BT_GETLINE_MINBUFLEN 64 |
| 17 | |
| 18 | static inline |
| 19 | char * _bt_getline_bufalloc(char **lineptr, size_t *n, size_t linelen) |
| 20 | { |
| 21 | size_t buflen = *n; |
| 22 | char *buf = *lineptr; |
| 23 | |
| 24 | if (buflen >= linelen && buf) { |
| 25 | return buf; |
| 26 | } |
| 27 | if (!buf) { |
| 28 | buflen = BT_GETLINE_MINBUFLEN; |
| 29 | } else { |
| 30 | buflen = buflen << 1; |
| 31 | if (buflen < BT_GETLINE_MINBUFLEN) { |
| 32 | buflen = BT_GETLINE_MINBUFLEN; |
| 33 | } |
| 34 | } |
| 35 | /* Check below not strictly needed, extra safety. */ |
| 36 | if (buflen < linelen) { |
| 37 | buflen = linelen; |
| 38 | } |
| 39 | buf = realloc(buf, buflen); |
| 40 | if (!buf) { |
| 41 | errno = ENOMEM; |
| 42 | return NULL; |
| 43 | } |
| 44 | *n = buflen; |
| 45 | *lineptr = buf; |
| 46 | return buf; |
| 47 | } |
| 48 | |
| 49 | /* |
| 50 | * Returns line length (including possible final \n, excluding final |
| 51 | * \0). On end of file, returns -1 with nonzero feof(stream) and errno |
| 52 | * set to 0. On error, returns -1 with errno set. |
| 53 | * |
| 54 | * This interface is similar to the getline(3) man page part of the |
| 55 | * Linux man-pages project, release 3.74. One major difference from the |
| 56 | * Open Group POSIX specification is that this implementation does not |
| 57 | * necessarily set the ferror() flag on error (because it is internal to |
| 58 | * libc). |
| 59 | */ |
| 60 | static inline |
| 61 | ssize_t bt_getline(char **lineptr, size_t *n, FILE *stream) |
| 62 | { |
| 63 | size_t linelen = 0; |
| 64 | char *buf; |
| 65 | int found_eof = 0; |
| 66 | |
| 67 | if (!lineptr || !n) { |
| 68 | errno = EINVAL; |
| 69 | return -1; |
| 70 | } |
| 71 | for (;;) { |
| 72 | char c; |
| 73 | int ret; |
| 74 | |
| 75 | ret = fgetc(stream); |
| 76 | if (ret == EOF) { |
| 77 | if (ferror(stream)) { |
| 78 | /* ferror() is set, errno set by fgetc(). */ |
| 79 | return -1; |
| 80 | } |
| 81 | BT_ASSERT_DBG(feof(stream)); |
| 82 | found_eof = 1; |
| 83 | break; |
| 84 | } |
| 85 | c = (char) ret; |
| 86 | if (linelen == SSIZE_MAX) { |
| 87 | errno = EOVERFLOW; |
| 88 | return -1; |
| 89 | } |
| 90 | buf = _bt_getline_bufalloc(lineptr, n, ++linelen); |
| 91 | if (!buf) { |
| 92 | return -1; |
| 93 | } |
| 94 | buf[linelen - 1] = c; |
| 95 | if (c == '\n') { |
| 96 | break; |
| 97 | } |
| 98 | } |
| 99 | if (!linelen && found_eof) { |
| 100 | /* feof() is set. */ |
| 101 | errno = 0; |
| 102 | return -1; |
| 103 | } |
| 104 | buf = _bt_getline_bufalloc(lineptr, n, ++linelen); |
| 105 | if (!buf) { |
| 106 | return -1; |
| 107 | } |
| 108 | buf[linelen - 1] = '\0'; |
| 109 | return linelen - 1; /* Count don't include final \0. */ |
| 110 | } |
| 111 | |
| 112 | #endif /* BABELTRACE_COMPAT_STDIO_H */ |