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/* vi: set sw=4 ts=4: */
/*
* config file parser helper
*
* Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
/*
Typical usage:
----- CUT -----
char *t[3]; // tokens placeholder
parser_t p; // parser structure
// open file
if (config_open(filename, &p)) {
// parse line-by-line
while (*config_read(&p, t, 3, 0, delimiters, comment_char) >= 0) { // 0..3 tokens
// use tokens
bb_error_msg("TOKENS: [%s][%s][%s]", t[0], t[1], t[2]);
}
...
// free parser
config_close(&p);
}
----- CUT -----
*/
FILE* FAST_FUNC config_open(parser_t *parser, const char *filename)
{
// empty file configures nothing!
parser->fp = fopen_or_warn(filename, "r");
if (!parser->fp)
return parser->fp;
// init parser
parser->line = NULL;
parser->lineno = 0;
return parser->fp;
}
void FAST_FUNC config_close(parser_t *parser)
{
free(parser->line);
free(parser->data);
fclose(parser->fp);
}
int FAST_FUNC config_read(parser_t *parser, char **tokens, int ntokens, int mintokens, const char *delims, char comment)
{
char *line, *q;
int token_num, len;
int noreduce = (ntokens < 0); // do not treat subsequent delimiters as one delimiter
if (ntokens < 0)
ntokens = -ntokens;
// nullify tokens
memset(tokens, 0, sizeof(void *) * ntokens);
// free used line
free(parser->line);
parser->line = NULL;
free(parser->data);
parser->data = NULL;
while (1) {
int n;
// get fresh line
//TODO: speed up xmalloc_fgetline by internally using fgets, not fgetc
line = xmalloc_fgetline(parser->fp);
if (!line)
return -1;
parser->lineno++;
// handle continuations. Tito's code stolen :)
while (1) {
len = strlen(line);
if (!len)
goto free_and_cont;
if (line[len - 1] != '\\')
break;
// multi-line object
line[--len] = '\0';
//TODO: add xmalloc_fgetline-like iface but with appending to existing str
q = xmalloc_fgetline(parser->fp);
if (q) {
parser->lineno++;
line = xasprintf("%s%s", line, q);
free(q);
}
}
// comments mean EOLs
if (comment) {
q = strchrnul(line, comment);
*q = '\0';
len = q - line;
}
// skip leading delimiters
n = strspn(line, delims);
if (n) {
len -= n;
strcpy(line, line + n);
}
if (len)
break;
// skip empty lines
free_and_cont:
free(line);
}
// non-empty line found, parse and return
// store line
parser->line = line = xrealloc(line, len + 1);
parser->data = xstrdup(line);
// now split line to tokens
//TODO: discard consecutive delimiters?
token_num = 0;
ntokens--; // now it's max allowed token no
while (1) {
// get next token
if (token_num == ntokens)
break;
q = line + strcspn(line, delims);
if (!*q)
break;
// pin token
*q++ = '\0';
if (noreduce || *line) {
tokens[token_num++] = line;
//bb_error_msg("L[%d] T[%s]", token_num, line);
}
line = q;
}
// non-empty remainder is also a token,
// so if ntokens <= 1, we just return the whole line
if (noreduce || *line)
tokens[token_num++] = line;
if (token_num < mintokens)
bb_error_msg_and_die("bad line %u: %d tokens found, %d needed",
parser->lineno, token_num, mintokens);
return token_num;
}
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