1 /* vi: set sw=4 ts=4: */
2 /*
3 * Utility routines.
4 *
5 * Copyright (C) 2005, 2006 Rob Landley <rob@landley.net>
6 * Copyright (C) 2004 Erik Andersen <andersen@codepoet.org>
7 * Copyright (C) 2001 Matt Krai
8 *
9 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 */
11 #include "libbb.h"
12
bb_get_chunk_from_file(FILE * file,size_t * end)13 char* FAST_FUNC bb_get_chunk_from_file(FILE *file, size_t *end)
14 {
15 int ch;
16 size_t idx = 0;
17 char *linebuf = NULL;
18
19 while ((ch = getc(file)) != EOF) {
20 /* grow the line buffer as necessary */
21 if (!(idx & 0xff)) {
22 if (idx == ((size_t)-1) - 0xff)
23 bb_die_memory_exhausted();
24 linebuf = xrealloc(linebuf, idx + 0x100);
25 }
26 linebuf[idx++] = (char) ch;
27 if (ch == '\0')
28 break;
29 if (end && ch == '\n')
30 break;
31 }
32 if (end)
33 *end = idx;
34 if (linebuf) {
35 // huh, does fgets discard prior data on error like this?
36 // I don't think so....
37 //if (ferror(file)) {
38 // free(linebuf);
39 // return NULL;
40 //}
41 linebuf = xrealloc(linebuf, idx + 1);
42 linebuf[idx] = '\0';
43 }
44 return linebuf;
45 }
46
47 /* Get line, including trailing \n if any */
xmalloc_fgets(FILE * file)48 char* FAST_FUNC xmalloc_fgets(FILE *file)
49 {
50 size_t i;
51
52 return bb_get_chunk_from_file(file, &i);
53 }
54 /* Get line. Remove trailing \n */
xmalloc_fgetline(FILE * file)55 char* FAST_FUNC xmalloc_fgetline(FILE *file)
56 {
57 size_t i;
58 char *c = bb_get_chunk_from_file(file, &i);
59
60 if (i && c[--i] == '\n')
61 c[i] = '\0';
62
63 return c;
64 }
65
66 #if 0
67 /* GNUism getline() should be faster (not tested) than a loop with fgetc */
68
69 /* Get line, including trailing \n if any */
70 char* FAST_FUNC xmalloc_fgets(FILE *file)
71 {
72 char *res_buf = NULL;
73 size_t res_sz;
74
75 if (getline(&res_buf, &res_sz, file) == -1) {
76 free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
77 res_buf = NULL;
78 }
79 //TODO: trimming to res_sz?
80 return res_buf;
81 }
82 /* Get line. Remove trailing \n */
83 char* FAST_FUNC xmalloc_fgetline(FILE *file)
84 {
85 char *res_buf = NULL;
86 size_t res_sz;
87
88 res_sz = getline(&res_buf, &res_sz, file);
89
90 if ((ssize_t)res_sz != -1) {
91 if (res_buf[res_sz - 1] == '\n')
92 res_buf[--res_sz] = '\0';
93 //TODO: trimming to res_sz?
94 } else {
95 free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
96 res_buf = NULL;
97 }
98 return res_buf;
99 }
100
101 #endif
102
103 #if 0
104 /* Faster routines (~twice as fast). +170 bytes. Unused as of 2008-07.
105 *
106 * NB: they stop at NUL byte too.
107 * Performance is important here. Think "grep 50gigabyte_file"...
108 * Ironically, grep can't use it because of NUL issue.
109 * We sorely need C lib to provide fgets which reports size!
110 *
111 * Update:
112 * Actually, uclibc and glibc have it. man getline. It's GNUism,
113 * but very useful one (if it's as fast as this code).
114 * TODO:
115 * - currently, sed and sort use bb_get_chunk_from_file and heavily
116 * depend on its "stop on \n or \0" behavior, and STILL they fail
117 * to handle all cases with embedded NULs correctly. So:
118 * - audit sed and sort; convert them to getline FIRST.
119 * - THEN ditch bb_get_chunk_from_file, replace it with getline.
120 * - provide getline implementation for non-GNU systems.
121 */
122
123 static char* xmalloc_fgets_internal(FILE *file, int *sizep)
124 {
125 int len;
126 int idx = 0;
127 char *linebuf = NULL;
128
129 while (1) {
130 char *r;
131
132 linebuf = xrealloc(linebuf, idx + 0x100);
133 r = fgets(&linebuf[idx], 0x100, file);
134 if (!r) {
135 /* need to terminate in case this is error
136 * (EOF puts NUL itself) */
137 linebuf[idx] = '\0';
138 break;
139 }
140 /* stupid. fgets knows the len, it should report it somehow */
141 len = strlen(&linebuf[idx]);
142 idx += len;
143 if (len != 0xff || linebuf[idx - 1] == '\n')
144 break;
145 }
146 *sizep = idx;
147 if (idx) {
148 /* xrealloc(linebuf, idx + 1) is up to caller */
149 return linebuf;
150 }
151 free(linebuf);
152 return NULL;
153 }
154
155 /* Get line, remove trailing \n */
156 char* FAST_FUNC xmalloc_fgetline_fast(FILE *file)
157 {
158 int sz;
159 char *r = xmalloc_fgets_internal(file, &sz);
160 if (r && r[sz - 1] == '\n')
161 r[--sz] = '\0';
162 return r; /* not xrealloc(r, sz + 1)! */
163 }
164
165 char* FAST_FUNC xmalloc_fgets(FILE *file)
166 {
167 int sz;
168 return xmalloc_fgets_internal(file, &sz);
169 }
170
171 /* Get line, remove trailing \n */
172 char* FAST_FUNC xmalloc_fgetline(FILE *file)
173 {
174 int sz;
175 char *r = xmalloc_fgets_internal(file, &sz);
176 if (!r)
177 return r;
178 if (r[sz - 1] == '\n')
179 r[--sz] = '\0';
180 return xrealloc(r, sz + 1);
181 }
182 #endif
183