aboutsummaryrefslogtreecommitdiff
path: root/lib/util/src/get_line.c
blob: 4273471b297d6d30f5774f415627f43bcde9f496 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
 * get_line.c
 *
 * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
 */
#include "util/parse.h"
#include "sqfs/io.h"
#include "sqfs/error.h"
#include "compat.h"

#include <stdlib.h>
#include <string.h>
#include <ctype.h>

void ltrim(char *buffer)
{
	size_t i = 0;

	while (isspace(buffer[i]))
		++i;

	if (i > 0)
		memmove(buffer, buffer + i, strlen(buffer + i) + 1);
}

void rtrim(char *buffer)
{
	size_t i = strlen(buffer);

	while (i > 0 && isspace(buffer[i - 1]))
		--i;

	buffer[i] = '\0';
}

void trim(char *buffer)
{
	ltrim(buffer);
	rtrim(buffer);
}

static size_t trim_flags(char *buffer, int flags)
{
	if (flags & ISTREAM_LINE_LTRIM)
		ltrim(buffer);

	if (flags & ISTREAM_LINE_RTRIM)
		rtrim(buffer);

	return strlen(buffer);
}

int istream_get_line(sqfs_istream_t *strm, char **out,
		     size_t *line_num, int flags)
{
	char *line = NULL, *new;
	size_t line_len = 0;
	int err;

	for (;;) {
		bool have_line = false;
		size_t i, count, avail;
		const sqfs_u8 *ptr;

		err = strm->get_buffered_data(strm, &ptr, &avail, 0);
		if (err < 0)
			goto fail;
		if (err > 0) {
			if (line_len == 0)
				goto out_eof;

			line_len = trim_flags(line, flags);
			if (line_len > 0 ||!(flags & ISTREAM_LINE_SKIP_EMPTY))
				break;

			goto out_eof;
		}

		for (i = 0; i < avail; ++i) {
			if (ptr[i] == '\n')
				break;
		}

		if (i < avail) {
			count = i++;
			have_line = true;
		} else {
			count = i;
		}

		new = realloc(line, line_len + count + 1);
		if (new == NULL) {
			err = SQFS_ERROR_ALLOC;
			goto fail;
		}

		line = new;
		memcpy(line + line_len, ptr, count);
		line_len += count;
		line[line_len] = '\0';

		strm->advance_buffer(strm, i);

		if (have_line) {
			if (line_len > 0 && line[line_len - 1] == '\r')
				line[--line_len] = '\0';

			line_len = trim_flags(line, flags);
			if (line_len > 0 || !(flags & ISTREAM_LINE_SKIP_EMPTY))
				break;

			free(line);
			line = NULL;
			*line_num += 1;
		}
	}

	new = realloc(line, line_len + 1);
	if (new != NULL)
		line = new;

	*out = line;
	return 0;
fail: {
	os_error_t temp = get_os_error_state();
	free(line);
	*out = NULL;
	set_os_error_state(temp);
	return err;
}
out_eof:
	free(line);
	*out = NULL;
	return 1;
}