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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* Copyright (C) 2018 - David Oberhollenzer
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef LIBCONFIG_H
#define LIBCONFIG_H
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
typedef struct {
const char *filename; /* input file name */
size_t lineno; /* current line number */
FILE *fp;
char *line;
int argc;
const char *const *argv;
} rdline_t;
typedef struct {
/* keyword to map the callback to */
const char *key;
/*
If set, allow grouping repetitions of the keyword in a single
multi line '{' ... '}' block. The callback is called for each
line.
*/
unsigned int allow_block : 1;
int (*handle)(void *obj, char *arg, rdline_t *rd, int flags);
} cfg_param_t;
/*
Initialize the config line scanner.
The scanner opens the filename relative to the passed dirfd. An
argument count and vector can be set for argument substitution
in rdline.
Returns 0 on success.
*/
int rdline_init(rdline_t *t, int dirfd, const char *filename,
int argc, const char *const *argv);
void rdline_cleanup(rdline_t *t);
/*
Read from file until end-of-file or a line feed is encountered.
Returns -1 on failure, +1 if end of file was reached,
0 if data was read successfully.
The following transformations are applied:
- Space characters are replaced with regular white space characters.
- Sequences of space characters are truncated to a single space.
- A '#' sign is interpreted as the start of a comment and removed,
together with everything that follows.
- Padding spaces are removed from the line.
- If a '"' is encounterd, the above rules are disabled, until a
after the matching '"' is read. A '"' can be escaped by preceeding
it with a backslash.
- If a second, coresponding '"' is not found, processing fails.
- If a '%' character is encountered, the next character is expected
to be a single digit index into argv. If it is not a digit or
outside the bounds set by argc, processing fails. On success,
the argv value is inserted and processed as described above.
- A '%' character can be escaped by writing '%%' or, if inside
a double quoted string, by writing \%.
- Arguments are pasted as is. Substitution is not recursive.
- If the resulting line is empty, processing is restarted.
*/
int rdline(rdline_t *t);
/*
Remove double quotes ('"') from a string and substitute escape
sequences in between double quotes.
*/
int unescape(char *src);
/*
Replace spaces in 'str' with null bytes. Tread strings (started and
terminated with double-quotes which can be escaped) as a single block.
Such strings are run through unescap(). All elements are tightly
packed together and the function returns the number of consecutive
argument strings that are now inside 'str'.
Returns a negative value if unescape() fails, a string is not
termianted or two such strings touch each other without a white
space in between.
*/
int pack_argv(char *str);
/*
Parse a configuration file containing '<keyword> [arguments...]' lines.
The cfgobj and flags are passed to the callback in the params array.
Returns zero on success.
*/
int rdcfg(void *cfgobj, rdline_t *rd, const cfg_param_t *params, size_t count,
int flags);
#endif /* LIBCONFIG_H */
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