Diff of /trunk/mkinitrd-magellan/busybox/libbb/get_line_from_file.c

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	revision 815 by niro, Sat Sep 1 22:45:15 2007 UTC	revision 816 by niro, Fri Apr 24 18:33:46 2009 UTC
#	Line 9	Line 9
9	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
10	*/	*/
11
12		/* for getline() [GNUism]
13		#ifndef _GNU_SOURCE
14		#define _GNU_SOURCE 1
15		#endif
16		*/
17	#include "libbb.h"	#include "libbb.h"
18
19	/* This function reads an entire line from a text file, up to a newline	/* This function reads an entire line from a text file, up to a newline
20	* or NUL byte, inclusive.  It returns a malloc'ed char * which must be	* or NUL byte, inclusive.  It returns a malloc'ed char * which
21	* stored and free'ed by the caller.  If end is NULL '\n' isn't considered	* must be free'ed by the caller.  If end is NULL '\n' isn't considered
22	* end of line.  If end isn't NULL, length of the chunk read is stored in it.	* end of line.  If end isn't NULL, length of the chunk is stored in it.
23	* Return NULL if EOF/error */	* If lineno is not NULL, *lineno is incremented for each line,
24		* and also trailing '\' is recognized as line continuation.
25	char *bb_get_chunk_from_file(FILE * file, int *end)	*
26		* Returns NULL if EOF/error. */
27		char* FAST_FUNC bb_get_chunk_with_continuation(FILE *file, int *end, int *lineno)
28	{	{
29	int ch;	int ch;
30	int idx = 0;	int idx = 0;
#	Line 27  char *bb_get_chunk_from_file(FILE * file	Line 34  char *bb_get_chunk_from_file(FILE * file
34	while ((ch = getc(file)) != EOF) {	while ((ch = getc(file)) != EOF) {
35	/* grow the line buffer as necessary */	/* grow the line buffer as necessary */
36	if (idx >= linebufsz) {	if (idx >= linebufsz) {
37	linebuf = xrealloc(linebuf, linebufsz += 80);	linebufsz += 256;
38		linebuf = xrealloc(linebuf, linebufsz);
39	}	}
40	linebuf[idx++] = (char) ch;	linebuf[idx++] = (char) ch;
41	if (!ch || (end && ch == '\n'))	if (!ch)
42	break;	break;
43		if (end && ch == '\n') {
44		if (lineno == NULL)
45		break;
46		(*lineno)++;
47		if (idx < 2 || linebuf[idx-2] != '\\')
48		break;
49		idx -= 2;
50		}
51	}	}
52	if (end)	if (end)
53	*end = idx;	*end = idx;
#	Line 42  char *bb_get_chunk_from_file(FILE * file	Line 58  char *bb_get_chunk_from_file(FILE * file
58	// free(linebuf);	// free(linebuf);
59	// return NULL;	// return NULL;
60	//}	//}
61	linebuf = xrealloc(linebuf, idx+1);	linebuf = xrealloc(linebuf, idx + 1);
62	linebuf[idx] = '\0';	linebuf[idx] = '\0';
63	}	}
64	return linebuf;	return linebuf;
65	}	}
66
67		char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end)
68		{
69		return bb_get_chunk_with_continuation(file, end, NULL);
70		}
71
72	/* Get line, including trailing \n if any */	/* Get line, including trailing \n if any */
73	char *xmalloc_fgets(FILE * file)	char* FAST_FUNC xmalloc_fgets(FILE *file)
74	{	{
75	int i;	int i;
76
77	return bb_get_chunk_from_file(file, &i);	return bb_get_chunk_from_file(file, &i);
78	}	}
79	/* Get line.  Remove trailing \n */	/* Get line.  Remove trailing \n */
80	char *xmalloc_getline(FILE * file)	char* FAST_FUNC xmalloc_fgetline(FILE *file)
81	{	{
82	int i;	int i;
83	char *c = bb_get_chunk_from_file(file, &i);	char *c = bb_get_chunk_from_file(file, &i);
#	Line 67  char *xmalloc_getline(FILE * file)	Line 87  char *xmalloc_getline(FILE * file)
87
88	return c;	return c;
89	}	}
90
91		#if 0
92		/* GNUism getline() should be faster (not tested) than a loop with fgetc */
93
94		/* Get line, including trailing \n if any */
95		char* FAST_FUNC xmalloc_fgets(FILE *file)
96		{
97		char *res_buf = NULL;
98		size_t res_sz;
99
100		if (getline(&res_buf, &res_sz, file) == -1) {
101		free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
102		res_buf = NULL;
103		}
104		//TODO: trimming to res_sz?
105		return res_buf;
106		}
107		/* Get line.  Remove trailing \n */
108		char* FAST_FUNC xmalloc_fgetline(FILE *file)
109		{
110		char *res_buf = NULL;
111		size_t res_sz;
112
113		res_sz = getline(&res_buf, &res_sz, file);
114
115		if ((ssize_t)res_sz != -1) {
116		if (res_buf[res_sz - 1] == '\n')
117		res_buf[--res_sz] = '\0';
118		//TODO: trimming to res_sz?
119		} else {
120		free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
121		res_buf = NULL;
122		}
123		return res_buf;
124		}
125
126		#endif
127
128		#if 0
129		/* Faster routines (~twice as fast). +170 bytes. Unused as of 2008-07.
130		*
131		* NB: they stop at NUL byte too.
132		* Performance is important here. Think "grep 50gigabyte_file"...
133		* Ironically, grep can't use it because of NUL issue.
134		* We sorely need C lib to provide fgets which reports size!
135		*
136		* Update:
137		* Actually, uclibc and glibc have it. man getline. It's GNUism,
138		*   but very useful one (if it's as fast as this code).
139		* TODO:
140		* - currently, sed and sort use bb_get_chunk_from_file and heavily
141		*   depend on its "stop on \n or \0" behavior, and STILL they fail
142		*   to handle all cases with embedded NULs correctly. So:
143		* - audit sed and sort; convert them to getline FIRST.
144		* - THEN ditch bb_get_chunk_from_file, replace it with getline.
145		* - provide getline implementation for non-GNU systems.
146		*/
147
148		static char* xmalloc_fgets_internal(FILE *file, int *sizep)
149		{
150		int len;
151		int idx = 0;
152		char *linebuf = NULL;
153
154		while (1) {
155		char *r;
156
157		linebuf = xrealloc(linebuf, idx + 0x100);
158		r = fgets(&linebuf[idx], 0x100, file);
159		if (!r) {
160		/* need to terminate in case this is error
161		* (EOF puts NUL itself) */
162		linebuf[idx] = '\0';
163		break;
164		}
165		/* stupid. fgets knows the len, it should report it somehow */
166		len = strlen(&linebuf[idx]);
167		idx += len;
168		if (len != 0xff || linebuf[idx - 1] == '\n')
169		break;
170		}
171		*sizep = idx;
172		if (idx) {
173		/* xrealloc(linebuf, idx + 1) is up to caller */
174		return linebuf;
175		}
176		free(linebuf);
177		return NULL;
178		}
179
180		/* Get line, remove trailing \n */
181		char* FAST_FUNC xmalloc_fgetline_fast(FILE *file)
182		{
183		int sz;
184		char *r = xmalloc_fgets_internal(file, &sz);
185		if (r && r[sz - 1] == '\n')
186		r[--sz] = '\0';
187		return r; /* not xrealloc(r, sz + 1)! */
188		}
189
190		char* FAST_FUNC xmalloc_fgets(FILE *file)
191		{
192		int sz;
193		return xmalloc_fgets_internal(file, &sz);
194		}
195
196		/* Get line, remove trailing \n */
197		char* FAST_FUNC xmalloc_fgetline(FILE *file)
198		{
199		int sz;
200		char *r = xmalloc_fgets_internal(file, &sz);
201		if (!r)
202		return r;
203		if (r[sz - 1] == '\n')
204		r[--sz] = '\0';
205		return xrealloc(r, sz + 1);
206		}
207		#endif

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