(Please reply to me also, I'm not an LKML subscriber)
strsep() looks a bit busted to to me. It fails to strip out preceeding
delimiters which may occur in front of the token(s) you're looking for.
I don't know if strsep() has been modified since 2.4.20 to fix this (or
perhaps someone will tell me this is the correct behaviour). The
following code is a small userland test app to illustrate the problem.
Thanks for reading,
Nat
=== simple usage:
#define STRSEP strsep /* pick one, to test functionality */
#define STRSEP strsep2
compile... gcc -o test test.c
./test ",,,4,,,5,,," /* STRSEP == strsep */
[1]',,4,,5,,': '' '' '4' '' '5' '' ''
/* note zero lenght tokens returned */
./test ",,4,,5,," /* STRSEP == strsep2 */
[1]' 4 5 ': '4' '5'
/* no more false zero len tokens */
=== code follows (apologies as importance/msglen approaches 0)
#include <stdio.h>
/* move past chars if found in set ct */
static char* strpbrkn(const char * cs,const char * ct)
{
const char *sc1,*sc2;
for( sc1 = cs; *sc1 != '\0'; ++sc1 ) {
for( sc2 = ct; *sc2 != '\0'; ++sc2 ) {
if( *sc1 == *sc2 )
break;
}
if( *sc2 == '\0' ) /* no chars in ct were found */
return(char*)sc1;
}
return NULL;
}
/* unchanged from kernel source string.c */
static char* strpbrk(const char * cs,const char * ct)
{
const char *sc1,*sc2;
for( sc1 = cs; *sc1 != '\0'; ++sc1 ) {
for( sc2 = ct; *sc2 != '\0'; ++sc2 ) {
if( *sc1 == *sc2 )
return(char *) sc1;
}
}
return NULL;
}
/* new strsep function */
char* strsep2(char **s, const char *ct)
{
char *beg = *s, *end;
if( beg == NULL )
return NULL;
beg = strpbrkn( beg, ct );
if( beg ) {
end = strpbrk( beg, ct );
if( end )
*end++ = '\0';
*s = end;
} else
*s = NULL;
return beg;
}
/* same old strsep */
char * strsep(char **s, const char *ct)
{
char *sbegin = *s, *end;
if (sbegin == NULL)
return NULL;
end = strpbrk(sbegin, ct);
if (end)
*end++ = '\0';
*s = end;
return sbegin;
}
#define STRSEP strsep
int main( int argc, char **argv )
{
int i;
const char *delim = " =\t\n\r,";
for( i = 1; i < argc; i++ ) {
char *tok, *ptr = argv[i];
printf( "[%d]'%s': ", i, ptr );
tok = STRSEP( &ptr, delim );
while( tok ) {
printf( "'%s' ", tok );
tok = STRSEP( &ptr, delim );
}
printf( "\n" );
fflush( stdout );
}
return 0;
}
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Nat Ersoz wrote:
> strsep() looks a bit busted to to me.
It is not. This is the expected behavior.
- --
- --------------. ,-. 444 Castro Street
Ulrich Drepper \ ,-----------------' \ Mountain View, CA 94041 USA
Red Hat `--' drepper at redhat.com `---------------------------
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