getting a folder name from a string in C

knobby67 · 04-04-2007, 04:54 AM

Hi,
can anyone advise is there a simple way to get a folder(s) name from a string passed to a function, in C.
For example I might have loadtext(const char *filename) where file name is Desktop/abc/alpla.txt and I need to store the folders so I'm left with a string Desktop/abc. So basically I strip the final file out of the name I pass. Hope this makes sense and thanks in advance.

Centinul · 04-04-2007, 06:15 AM

You could try using Perl Compatible Regular Expressions in C.

They are kind of a pain to learn but once you get the hang of it they are not too bad and VERY powerful.

Hope this helps!

Nick_Battle · 04-04-2007, 08:06 AM

If you just want to locate the last "/", strrchr(3) will do the trick. If you replace the pointer returned with a null, it will crop the string to just be the directory name. Be careful if "/something" is passed though!

HTH,
-nick

knobby67 · 04-04-2007, 09:47 AM

Thank Chaps! I went with the string function, perl seemed a bit of a long way round though I'm sure educational
I used

int s1;
char *p,*name;
int loop=0;

char *n="text.txt"; /*test*/

p=strrchr(filename,'/'); /*get final / put error here for null*/
s1=strlen((filename)-strlen(p))+1;
name=malloc(s1);
memcpy (name, filename, s1);

printf(" %d\n",s1); /*view results*/
printf(" %s \n",name);

strcat(name,n);
printf(" %s \n",name);

Wouldn't you think C would have a function for this?

Nick_Battle · 04-11-2007, 07:04 AM

There are the basename and dirname functions, which do the same sort of thing, but you still have to concatenate and copy the strings you want.

http://www.die.net/doc/linux/man/man3/dirname.3.html

HTH,
-nick