hush: get rid of charmap[]
[oweals/busybox.git] / libbb / fgets_str.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Utility routines.
4  *
5  * Copyright (C) many different people.
6  * If you wrote this, please acknowledge your work.
7  *
8  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9  */
10
11 #include "libbb.h"
12
13 static char *xmalloc_fgets_internal(FILE *file, const char *terminating_string, int chop_off, size_t *maxsz_p)
14 {
15         char *linebuf = NULL;
16         const int term_length = strlen(terminating_string);
17         int end_string_offset;
18         int linebufsz = 0;
19         int idx = 0;
20         int ch;
21         size_t maxsz = *maxsz_p;
22
23         while (1) {
24                 ch = fgetc(file);
25                 if (ch == EOF) {
26                         if (idx == 0)
27                                 return linebuf; /* NULL */
28                         break;
29                 }
30
31                 if (idx >= linebufsz) {
32                         linebufsz += 200;
33                         linebuf = xrealloc(linebuf, linebufsz);
34                         if (idx >= maxsz) {
35                                 linebuf[idx] = ch;
36                                 idx++;
37                                 break;
38                         }
39                 }
40
41                 linebuf[idx] = ch;
42                 idx++;
43
44                 /* Check for terminating string */
45                 end_string_offset = idx - term_length;
46                 if (end_string_offset >= 0
47                  && memcmp(&linebuf[end_string_offset], terminating_string, term_length) == 0
48                 ) {
49                         if (chop_off)
50                                 idx -= term_length;
51                         break;
52                 }
53         }
54         /* Grow/shrink *first*, then store NUL */
55         linebuf = xrealloc(linebuf, idx + 1);
56         linebuf[idx] = '\0';
57         *maxsz_p = idx;
58         return linebuf;
59 }
60
61 /* Read up to TERMINATING_STRING from FILE and return it,
62  * including terminating string.
63  * Non-terminated string can be returned if EOF is reached.
64  * Return NULL if EOF is reached immediately.  */
65 char* FAST_FUNC xmalloc_fgets_str(FILE *file, const char *terminating_string)
66 {
67         size_t maxsz = INT_MAX - 4095;
68         return xmalloc_fgets_internal(file, terminating_string, 0, &maxsz);
69 }
70
71 char* FAST_FUNC xmalloc_fgets_str_len(FILE *file, const char *terminating_string, size_t *maxsz_p)
72 {
73         size_t maxsz;
74
75         if (!maxsz_p) {
76                 maxsz = INT_MAX - 4095;
77                 maxsz_p = &maxsz;
78         }
79         return xmalloc_fgets_internal(file, terminating_string, 0, maxsz_p);
80 }
81
82 char* FAST_FUNC xmalloc_fgetline_str(FILE *file, const char *terminating_string)
83 {
84         size_t maxsz = INT_MAX - 4095;
85         return xmalloc_fgets_internal(file, terminating_string, 1, &maxsz);
86 }