libbb: unified config parser (By Vladimir Dronnikov)

mdev: use it

function                                             old     new   delta
config_read                                            -     400    +400
config_open                                            -      43     +43
config_close                                           -       9      +9
qrealloc                                              33      36      +3
compare_keys                                         735     737      +2
xstrtoull_range_sfx                                  296     295      -1
qgravechar                                           109     106      -3
get_address                                          181     178      -3
next_token                                           928     923      -5
sv_main                                             1228    1222      -6
find_main                                            418     406     -12
next_field                                            32       -     -32
make_device                                         1269    1184     -85
------------------------------------------------------------------------------
(add/remove: 3/1 grow/shrink: 2/7 up/down: 457/-147)          Total: 310 bytes
This commit is contained in:
Denis Vlasenko 2008-07-15 21:09:30 +00:00
parent 0ed090e184
commit e559e0a757
4 changed files with 295 additions and 56 deletions

View File

@ -987,6 +987,28 @@ int bb_ask_confirmation(void) FAST_FUNC;
extern int bb_parse_mode(const char* s, mode_t* theMode) FAST_FUNC;
/*
* Uniform config file parser helpers
*/
#define PARSER_STDIO_BASED 1
#if !PARSER_STDIO_BASED
typedef struct parser_t {
char *data;
char *line;
int lineno;
} parser_t;
extern char* config_open(parser_t *parser, const char *filename) FAST_FUNC;
#else
typedef struct parser_t {
FILE *fp;
char *line;
int lineno;
} parser_t;
extern FILE* config_open(parser_t *parser, const char *filename) FAST_FUNC;
#endif
extern char* config_read(parser_t *parser, char **tokens, int ntokens, int mintokens, const char *delims, char comment) FAST_FUNC;
extern void config_close(parser_t *parser) FAST_FUNC;
/* Concatenate path and filename to new allocated buffer.
* Add "/" only as needed (no duplicate "//" are produced).
* If path is NULL, it is assumed to be "/".

View File

@ -63,6 +63,7 @@ lib-y += mode_string.o
lib-y += mtab_file.o
lib-y += obscure.o
lib-y += parse_mode.o
lib-y += parse_config.o
lib-y += perror_msg.o
lib-y += perror_msg_and_die.o
lib-y += perror_nomsg.o

247
libbb/parse_config.c Normal file
View File

@ -0,0 +1,247 @@
/* 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..3 tokens
// use tokens
bb_error_msg("TOKENS: [%s][%s][%s]", t[0], t[1], t[2]);
}
...
// free parser
config_close(&p);
}
----- CUT -----
*/
#if !PARSER_STDIO_BASED
char* FAST_FUNC config_open(parser_t *parser, const char *filename)
{
// empty file configures nothing!
char *data = xmalloc_open_read_close(filename, NULL);
if (!data)
return data;
// convert 0x5c 0x0a (backslashes at the very end of line) to 0x20 0x20 (spaces)
for (char *s = data; (s = strchr(s, '\\')) != NULL; ++s)
if ('\n' == s[1]) {
s[0] = s[1] = ' ';
}
// init parser
parser->line = parser->data = data;
parser->lineno = 0;
return data;
}
void FAST_FUNC config_close(parser_t *parser)
{
// for now just free config data
free(parser->data);
}
char* FAST_FUNC config_read(parser_t *parser, char **tokens, int ntokens, int mintokens, const char *delims, char comment)
{
char *ret, *line;
int noreduce = (ntokens<0); // do not treat subsequent delimiters as one delimiter
if (ntokens < 0)
ntokens = -ntokens;
ret = line = parser->line;
// nullify tokens
memset(tokens, 0, sizeof(void *) * ntokens);
// now split to lines
while (*line) {
int token_num = 0;
// limit the line
char *ptr = strchrnul(line, '\n');
*ptr++ = '\0';
// line number
parser->lineno++;
// comments mean EOLs
if (comment)
*strchrnul(line, comment) = '\0';
// skip leading delimiters
while (*line && strchr(delims, *line))
line++;
// skip empty lines
if (*line) {
char *s;
// now split line to tokens
s = line;
while (s) {
char *p;
// get next token
if (token_num+1 >= ntokens)
break;
p = s;
while (*p && !strchr(delims, *p))
p++;
if (!*p)
break;
*p++ = '\0';
// pin token
if (noreduce || *s) {
tokens[token_num++] = s;
//bb_error_msg("L[%d] T[%s]", token_num, s);
}
s = p;
}
// non-empty remainder is also a token. So if ntokens == 0, we just return the whole line
if (s && (noreduce || *s))
tokens[token_num++] = s;
// sanity check: have we got all required tokens?
if (token_num < mintokens)
bb_error_msg_and_die("bad line %u, %d tokens found, %d needed", parser->lineno, token_num, mintokens);
// advance data for the next call
line = ptr;
break;
}
// line didn't contain any token -> try next line
ret = line = ptr;
}
parser->line = line;
// return current line. caller must check *ret to determine whether to continue
return ret;
}
#else // stdio-based
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)
{
fclose(parser->fp);
}
char* 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;
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 line;
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);
// 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 parser->line; // maybe token_num instead?
}
#endif

View File

@ -25,16 +25,6 @@ struct globals {
/* We use additional 64+ bytes in make_device() */
#define SCRATCH_SIZE 80
static char *next_field(char *s)
{
char *end = skip_non_whitespace(s);
s = skip_whitespace(end);
*end = '\0';
if (*s == '\0')
s = NULL;
return s;
}
/* Builds an alias path.
* This function potentionally reallocates the alias parameter.
*/
@ -104,33 +94,26 @@ static void make_device(char *path, int delete)
type = S_IFBLK;
if (ENABLE_FEATURE_MDEV_CONF) {
FILE *fp;
char *line, *val, *next;
unsigned lineno = 0;
parser_t parser;
char *tokens[5];
/* If we have config file, look up user settings */
fp = fopen_or_warn("/etc/mdev.conf", "r");
if (!fp)
if (!config_open(&parser, "/etc/mdev.conf"))
goto end_parse;
while ((line = xmalloc_fgetline(fp)) != NULL) {
while (config_read(&parser, tokens, 4, 3, " \t", '#')) {
regmatch_t off[1+9*ENABLE_FEATURE_MDEV_RENAME_REGEXP];
++lineno;
trim(line);
if (!line[0])
goto next_line;
char *val;
/* Fields: regex uid:gid mode [alias] [cmd] */
/* 1st field: regex to match this device */
next = next_field(line);
{
regex_t match;
int result;
/* Is this it? */
xregcomp(&match, line, REG_EXTENDED);
xregcomp(&match, tokens[0], REG_EXTENDED);
result = regexec(&match, device_name, ARRAY_SIZE(off), off, 0);
regfree(&match);
@ -147,7 +130,7 @@ static void make_device(char *path, int delete)
if (result || off[0].rm_so
|| ((int)off[0].rm_eo != (int)strlen(device_name))
) {
goto next_line;
continue;
}
}
@ -155,15 +138,11 @@ static void make_device(char *path, int delete)
* after parsing the rest of fields */
/* 2nd field: uid:gid - device ownership */
if (!next) /* field must exist */
bb_error_msg_and_die("bad line %u", lineno);
val = next;
next = next_field(val);
{
struct passwd *pass;
struct group *grp;
char *str_uid = val;
char *str_gid = strchrnul(val, ':');
char *str_uid = tokens[1];
char *str_gid = strchrnul(str_uid, ':');
if (*str_gid)
*str_gid++ = '\0';
@ -182,33 +161,30 @@ static void make_device(char *path, int delete)
}
/* 3rd field: mode - device permissions */
if (!next) /* field must exist */
bb_error_msg_and_die("bad line %u", lineno);
val = next;
next = next_field(val);
mode = strtoul(val, NULL, 8);
mode = strtoul(tokens[2], NULL, 8);
val = tokens[3];
/* 4th field (opt): >alias */
#if ENABLE_FEATURE_MDEV_RENAME
if (!next)
if (!val)
break;
if (*next == '>' || *next == '=') {
#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
aliaslink = *val;
if (aliaslink == '>' || aliaslink == '=') {
char *s, *p;
unsigned i, n;
aliaslink = *next;
val = next;
next = next_field(val);
char *a = val;
s = strchr(val, ' ');
val = (s && s[1]) ? s+1 : NULL;
#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
/* substitute %1..9 with off[1..9], if any */
n = 0;
s = val;
s = a;
while (*s)
if (*s++ == '%')
n++;
p = alias = xzalloc(strlen(val) + n * strlen(device_name));
s = val + 1;
p = alias = xzalloc(strlen(a) + n * strlen(device_name));
s = a + 1;
while (*s) {
*p = *s;
if ('%' == *s) {
@ -224,24 +200,20 @@ static void make_device(char *path, int delete)
s++;
}
#else
aliaslink = *next;
val = next;
next = next_field(val);
alias = xstrdup(val + 1);
alias = xstrdup(a + 1);
#endif
}
#endif /* ENABLE_FEATURE_MDEV_RENAME */
/* The rest (opt): command to run */
if (!next)
if (!val)
break;
val = next;
if (ENABLE_FEATURE_MDEV_EXEC) {
const char *s = "@$*";
const char *s2 = strchr(s, *val);
if (!s2)
bb_error_msg_and_die("bad line %u", lineno);
bb_error_msg_and_die("bad line %u", parser.lineno);
/* Correlate the position in the "@$*" with the delete
* step so that we get the proper behavior:
@ -255,12 +227,9 @@ static void make_device(char *path, int delete)
}
/* end of field parsing */
break; /* we found matching line, stop */
next_line:
free(line);
} /* end of "while line is read from /etc/mdev.conf" */
free(line); /* in case we used "break" to get here */
fclose(fp);
config_close(&parser);
}
end_parse: