jean-pierre charras d17cef95fd Add an other markdown to html converter (sundown), better to convert markdown.
The previous converter (maddy) is still available, during some time.
We therefore have the time to choose between them.
sundown is better to convert a md text, but is written to C
maddy has a few issues to convert a md text, but is written to C++
Both have no dependency.
2019-10-01 18:53:23 +02:00

308 lines
7.2 KiB
C

/*
* Copyright (c) 2011, Vicent Marti
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "buffer.h"
#include "autolink.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#if defined(_WIN32)
#define strncasecmp _strnicmp
#endif
int sd_autolink_issafe( const uint8_t* link, size_t link_len )
{
static const size_t valid_uris_count = 5;
static const char* valid_uris[] =
{
"/", "http://", "https://", "ftp://", "mailto:"
};
size_t i;
for( i = 0; i < valid_uris_count; ++i )
{
size_t len = strlen( valid_uris[i] );
if( link_len > len
&& strncasecmp( (char*) link, valid_uris[i], len ) == 0
&& isalnum( link[len] ) )
return 1;
}
return 0;
}
static size_t autolink_delim( uint8_t* data, size_t link_end, size_t max_rewind, size_t size )
{
uint8_t cclose, copen = 0;
size_t i;
for( i = 0; i < link_end; ++i )
if( data[i] == '<' )
{
link_end = i;
break;
}
while( link_end > 0 )
{
if( strchr( "?!.,", data[link_end - 1] ) != NULL )
link_end--;
else if( data[link_end - 1] == ';' )
{
size_t new_end = link_end - 2;
while( new_end > 0 && isalpha( data[new_end] ) )
new_end--;
if( new_end < link_end - 2 && data[new_end] == '&' )
link_end = new_end;
else
link_end--;
}
else
break;
}
if( link_end == 0 )
return 0;
cclose = data[link_end - 1];
switch( cclose )
{
case '"':
copen = '"'; break;
case '\'':
copen = '\''; break;
case ')':
copen = '('; break;
case ']':
copen = '['; break;
case '}':
copen = '{'; break;
}
if( copen != 0 )
{
size_t closing = 0;
size_t opening = 0;
size_t i = 0;
/* Try to close the final punctuation sign in this same line;
* if we managed to close it outside of the URL, that means that it's
* not part of the URL. If it closes inside the URL, that means it
* is part of the URL.
*
* Examples:
*
* foo http://www.pokemon.com/Pikachu_(Electric) bar
* => http://www.pokemon.com/Pikachu_(Electric)
*
* foo (http://www.pokemon.com/Pikachu_(Electric)) bar
* => http://www.pokemon.com/Pikachu_(Electric)
*
* foo http://www.pokemon.com/Pikachu_(Electric)) bar
* => http://www.pokemon.com/Pikachu_(Electric))
*
* (foo http://www.pokemon.com/Pikachu_(Electric)) bar
* => foo http://www.pokemon.com/Pikachu_(Electric)
*/
while( i < link_end )
{
if( data[i] == copen )
opening++;
else if( data[i] == cclose )
closing++;
i++;
}
if( closing != opening )
link_end--;
}
return link_end;
}
static size_t check_domain( uint8_t* data, size_t size, int allow_short )
{
size_t i, np = 0;
if( !isalnum( data[0] ) )
return 0;
for( i = 1; i < size - 1; ++i )
{
if( data[i] == '.' )
np++;
else if( !isalnum( data[i] ) && data[i] != '-' )
break;
}
if( allow_short )
{
/* We don't need a valid domain in the strict sense (with
* least one dot; so just make sure it's composed of valid
* domain characters and return the length of the the valid
* sequence. */
return i;
}
else
{
/* a valid domain needs to have at least a dot.
* that's as far as we get */
return np ? i : 0;
}
}
size_t sd_autolink__www( size_t* rewind_p, struct buf* link, uint8_t* data,
size_t max_rewind, size_t size, unsigned int flags )
{
size_t link_end;
if( max_rewind > 0 && !ispunct( data[-1] ) && !isspace( data[-1] ) )
return 0;
if( size < 4 || memcmp( data, "www.", strlen( "www." ) ) != 0 )
return 0;
link_end = check_domain( data, size, 0 );
if( link_end == 0 )
return 0;
while( link_end < size && !isspace( data[link_end] ) )
link_end++;
link_end = autolink_delim( data, link_end, max_rewind, size );
if( link_end == 0 )
return 0;
bufput( link, data, link_end );
*rewind_p = 0;
return (int) link_end;
}
size_t sd_autolink__email( size_t* rewind_p, struct buf* link, uint8_t* data,
size_t max_rewind, size_t size, unsigned int flags )
{
size_t link_end, rewind;
int nb = 0, np = 0;
for( rewind = 0; rewind < max_rewind; ++rewind )
{
uint8_t c = data[-rewind - 1];
if( isalnum( c ) )
continue;
if( strchr( ".+-_", c ) != NULL )
continue;
break;
}
if( rewind == 0 )
return 0;
for( link_end = 0; link_end < size; ++link_end )
{
uint8_t c = data[link_end];
if( isalnum( c ) )
continue;
if( c == '@' )
nb++;
else if( c == '.' && link_end < size - 1 )
np++;
else if( c != '-' && c != '_' )
break;
}
if( link_end < 2 || nb != 1 || np == 0
|| !isalpha( data[link_end - 1] ) )
return 0;
link_end = autolink_delim( data, link_end, max_rewind, size );
if( link_end == 0 )
return 0;
bufput( link, data - rewind, link_end + rewind );
*rewind_p = rewind;
return link_end;
}
size_t sd_autolink__url( size_t* rewind_p, struct buf* link, uint8_t* data,
size_t max_rewind, size_t size, unsigned int flags )
{
size_t link_end, rewind = 0, domain_len;
if( size < 4 || data[1] != '/' || data[2] != '/' )
return 0;
while( rewind < max_rewind && isalpha( data[-rewind - 1] ) )
rewind++;
if( !sd_autolink_issafe( data - rewind, size + rewind ) )
return 0;
link_end = strlen( "://" );
domain_len = check_domain(
data + link_end,
size - link_end,
flags & SD_AUTOLINK_SHORT_DOMAINS );
if( domain_len == 0 )
return 0;
link_end += domain_len;
while( link_end < size && !isspace( data[link_end] ) )
link_end++;
link_end = autolink_delim( data, link_end, max_rewind, size );
if( link_end == 0 )
return 0;
bufput( link, data - rewind, link_end + rewind );
*rewind_p = rewind;
return link_end;
}