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