pointer to string.

hi im trying to split up a string e.g: execute -b / run -r / shout -s into 2 different strings.

*First array of strings will contain the following, with "/" taken out:
1st string: buffer[0]=execute -b
2nd string: buffer[1]=run -r
3rd string: buffer[2]=shout -a

*Second array of strings will contain a further tokenized string of each word before any flags:
1st string: buffer2[0]=execute
2nd string: buffer2[1]=run
3rd string: buffer2[2]=shout

i came out with this rough idea but im still uncertain at some parts and i hope someone would show me where there might be problems.

Code:

char* temp;
char** buffer;       /* i do not have a definite size to malloc this, wat should specify for the 
char** buffer2;      * size for malloc? */
int i;                     

i=0;
temp = strtok(somevalue, "/");
while (temp) {
  buffer[i] = temp;
  strtok(NULL, "/");
  i++;
}

/* loop through buffer */
for( i = 0; i < sizeof(buffer); i++) {   /* can i actually loop all the contents of the string array
     temp = strtok(buffer[i], " ");         * like that? */
     
     buffer2[i] = temp;
     
}

Is there a more efficient or shorter way to produce the same result ?

You can definetely use strtok for this. I think it is appropriate. If you don't want to damage your input in anyway, you can try my strtok.
Remember that your code is illegal because you are using unallocated buffers. If you don't know the size, then you must guess. And if it just isn't big enough, allocate some more.
But even so, you can query the size because strtok truncates the string array. Then you can allocate.

for the second loop, size of buffer will returns the size of memory i allocate for the buffer right? in dat case, if i loop thru the array using the following code, will it be a problem?

Code:

/* loop through buffer */
for( i = 0; i < sizeof(buffer); i++) {   /* can i actually loop all the contents of the string array
     temp = strtok(buffer[i], " ");         * like that? */
     
     buffer2[i] = temp;
     
}

I don't think you quite get how strtok works. It truncates your string and returns the original pointer. You need to allocate or have a big enough buffer to copy that.
Then you call strtok again until it returns NULL I think.
You can see my strtok. It has full source. It's also non-damaging.

oh.. what i actually meant was for

for( i = 0; i < sizeof(buffer); i++)

if i do a malloc of buffer=(char**)malloc(1000); for example.
does sizeof retrieves 1000 or will it jus get the array size?

Originally Posted by cstudent

oh.. what i actually meant was for

for( i = 0; i < sizeof(buffer); i++)

if i do a malloc of buffer=(char**)malloc(1000); for example.
does sizeof retrieves 1000 or will it jus get the array size?

Using sizeof() on a pointer will return 4 (or 8 on some machines), not the size of the allocation that the pointer points to. You need to "remember" the size of the the allocation yourself.

--
Mats

right thanks