1
0
mirror of https://github.com/mpv-player/mpv synced 2024-12-10 08:56:04 +00:00
mpv/subopt-helper.c

335 lines
9.0 KiB
C
Raw Normal View History

/**
* \file subopt-helper.c
*
* \brief Compensates the suboption parsing code duplication a bit.
*
* The routines defined below are there to help you with the
* suboption parsing. Meaning extracting the options and their
* values for you and also outputting generic help message if
* a parse error is encountered.
*
* Most stuff happens in the subopt_parse function: if you call it
* it parses for the passed opts in the passed string. It calls some
* extra functions for explicit argument parsing ( where the option
* itself isn't the argument but a value given after the argument
* delimiter ('='). It also calls your test function if you supplied
* one.
*
*/
#include "subopt-helper.h"
#include "mp_msg.h"
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <assert.h>
#ifndef MPDEBUG
#define NDEBUG
#endif
/* prototypes for argument parsing */
static char const * parse_int( char const * const str, int * const valp );
static char const * parse_str( char const * const str, strarg_t * const valp );
static char const * parse_float( char const * const str, float * const valp );
/**
* \brief Try to parse all options in str and fail if it was not possible.
*
* \param str Pointer to the zero terminated string to be parsed.
* \param opts Pointer to a options array. The array must be terminated
* with an element having set name to NULL in its opt_t structure.
*
* \return The return value is zero if the string could be parsed
* else a non-zero value is returned.
*
*/
int subopt_parse( char const * const str, const opt_t * opts )
{
int parse_err = 0, idx;
unsigned int parse_pos = 0;
if ( str )
{
while ( str[parse_pos] && !parse_err )
{
int next = 0;
idx = 0; // reset index for the below loop
while ( opts[idx].name )
{
int opt_len;
int substr_len;
// get length of the option we test against */
opt_len = strlen( opts[idx].name );
// get length of the current substring of str */
{
char * delim, * arg_delim;
/* search nearest delimiter ( option or argument delimiter ) */
delim = strchr( &str[parse_pos], ':' );
arg_delim = strchr( &str[parse_pos], '=' );
if ( ( delim && arg_delim && delim > arg_delim ) ||
delim == NULL )
{
delim = strchr( &str[parse_pos], '=' );
}
substr_len = delim ? // is a delim present
delim - &str[parse_pos] : // yes
strlen( &str[parse_pos] ); // no, end of string
}
//printf( "substr_len=%d, opt_len=%d\n", substr_len, opt_len );
/* Check if the length of the current option matches the *
* length of the option we want to test again. */
if ( substr_len == opt_len )
{
/* check if option was activated/deactivated */
if( strncmp( &str[parse_pos], opts[idx].name, opt_len ) == 0 )
{
/* option was found */
next = 1;
assert( opts[idx].valp && "Need a pointer to store the arg!" );
/* type specific code */
if ( opts[idx].type == OPT_ARG_BOOL )
{
/* Handle OPT_ARG_BOOL separately so *
* the others can share code. */
/* set option to true */
*((int *)(opts[idx].valp)) = 1;
/* increment position */
parse_pos += opt_len;
}
else
{
/* Type is not OPT_ARG_BOOL, means we have to parse *
* for the arg delimiter character and eventually *
* call a test function. */
char const * last;
/* increment position to check for arg */
parse_pos += opt_len;
if ( str[parse_pos] != '=' )
{
parse_err = 1; break;
}
/* '=' char was there, so let's move after it */
++parse_pos;
switch ( opts[idx].type )
{
case OPT_ARG_INT:
last = parse_int( &str[parse_pos],
(int *)opts[idx].valp );
break;
case OPT_ARG_STR:
last = parse_str( &str[parse_pos],
(strarg_t *)opts[idx].valp );
break;
case OPT_ARG_MSTRZ:
{
char **valp = opts[idx].valp;
strarg_t tmp;
tmp.str = NULL;
tmp.len = 0;
last = parse_str( &str[parse_pos], &tmp );
if (*valp)
free(*valp);
*valp = NULL;
if (tmp.str && tmp.len > 0) {
*valp = malloc(tmp.len + 1);
memcpy(*valp, tmp.str, tmp.len);
(*valp)[tmp.len] = 0;
}
break;
}
case OPT_ARG_FLOAT:
last = parse_float( &str[parse_pos],
(float *)opts[idx].valp );
break;
default:
assert( 0 && "Arg type of suboption doesn't exist!" );
last = NULL; // break parsing!
}
/* was the conversion succesful? */
if ( !last )
{
parse_err = 1; break;
}
/* make test if supplied */
if ( opts[idx].test && !opts[idx].test( opts[idx].valp ) )
{
parse_err = 1; break;
}
/* we succeded, set position */
parse_pos = last - str;
}
}
}
else if ( substr_len == opt_len+2 )
{
if ( opts[idx].type == OPT_ARG_BOOL && // check for no<opt>
strncmp( &str[parse_pos], "no", 2 ) == 0 &&
strncmp( &str[parse_pos+2], opts[idx].name, opt_len ) == 0 )
{
/* option was found but negated */
next = 1;
/* set arg to false */
*((int *)(opts[idx].valp)) = 0;
/* increment position */
parse_pos += opt_len+2;
}
}
++idx; // test against next option
/* break out of the loop, if this subopt is processed */
if ( next ) { break; }
}
/* if we had a valid suboption the current pos should *
* equal the delimiter char, which should be ':' for *
* suboptions. */
if ( !parse_err && str[parse_pos] == ':' ) { ++parse_pos; }
else if ( str[parse_pos] ) { parse_err = 1; }
}
}
/* if an error was encountered */
if (parse_err)
{
unsigned int i;
mp_msg( MSGT_VO, MSGL_FATAL, "Could not parse arguments at the position indicated below:\n%s\n", str );
for ( i = 0; i < parse_pos; ++i )
{
mp_msg(MSGT_VO, MSGL_FATAL, " ");
}
mp_msg(MSGT_VO, MSGL_FATAL, "^\n");
return -1;
}
/* we could parse everything */
return 0;
}
static char const * parse_int( char const * const str, int * const valp )
{
char * endp;
assert( str && "parse_int(): str == NULL" );
*valp = (int)strtol( str, &endp, 0 );
/* nothing was converted */
if ( str == endp ) { return NULL; }
return endp;
}
static char const * parse_float( char const * const str, float * const valp )
{
char * endp;
assert( str && "parse_float(): str == NULL" );
*valp = strtod( str, &endp );
/* nothing was converted */
if ( str == endp ) { return NULL; }
return endp;
}
#define QUOTE_CHAR '%'
static char const * parse_str( char const * str, strarg_t * const valp )
{
char const * match = strchr( str, ':' );
if (str[0] == QUOTE_CHAR) {
int len = 0;
str = &str[1];
len = (int)strtol(str, (char **)&str, 0);
if (!str || str[0] != QUOTE_CHAR || (len > strlen(str) - 1))
return NULL;
str = &str[1];
match = &str[len];
}
else
if (str[0] == '"') {
str = &str[1];
match = strchr(str, '"');
if (!match)
return NULL;
valp->len = match - str;
valp->str = str;
return &match[1];
}
if ( !match )
match = &str[strlen(str)];
// empty string or too long
if ((match == str) || (match - str > INT_MAX))
return NULL;
valp->len = match - str;
valp->str = str;
return match;
}
/*** common test functions ***/
/** \brief Test if i is not negative */
int int_non_neg( int * i )
{
if ( *i < 0 ) { return 0; }
return 1;
}
/** \brief Test if i is positive. */
int int_pos( int * i )
{
if ( *i > 0 ) { return 1; }
return 0;
}
/*** little helpers */
/** \brief compare the stings just as strcmp does */
int strargcmp(strarg_t *arg, const char *str) {
int res = strncmp(arg->str, str, arg->len);
if (!res && arg->len != strlen(str))
res = arg->len - strlen(str);
return res;
}
/** \brief compare the stings just as strcasecmp does */
int strargcasecmp(strarg_t *arg, char *str) {
int res = strncasecmp(arg->str, str, arg->len);
if (!res && arg->len != strlen(str))
res = arg->len - strlen(str);
return res;
}