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strtok help

Posted on 2001-07-10
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Last Modified: 2008-02-01
if i have

char szText[] = "test?blah?123";

and i want to use strtok to seperate the text on the ? and i want to assign each segment to a 100 byte buffer in

char *pszBuffer;
pszBuffer = malloc (10 * 100);

how would i do it with strtok? i cant figure it out.
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Question by:Kitty__Kong
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7 Comments
 
LVL 2

Accepted Solution

by:
MadYugoslav earned 150 total points
ID: 6268384
char szText[] = "test?blah?123";char seps[]   = " ,\t\n";
char *token;
char *pszBuffer;

void GetLines( void )
{
   int i=0;
   pszBuffer = malloc (10 * 100);
   token = strtok( szText, "?" );
   while( token != NULL )
   {
      strcpy(pszBuffer[i*100], token
      i++;
      token = strtok( NULL, "?" );
   }
}

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LVL 10

Expert Comment

by:makerp
ID: 6268551
here is a function i wrote a while back to strtok and return a array of pointers, it aint perfect and probably could be improved but it works

/* function to take a string and split it up into parts separted by
   seperator . returns a pointer to pointers !! */
char **splitText(const char *text, int *count, char* seperator)
{
     char **lines = NULL;
     char *ptr = NULL, *temp;
     int size = 0;
     /* set the count to one just in case */
     *count = 0;
     temp = (char*)malloc(strlen(text) + 1);
     if(!temp)
     {
          return NULL;
     }
     strcpy(temp,text);
     ptr = strtok(temp,seperator);
     while(ptr != NULL)
     {
          if(lines)
          {
                    size = _msize(lines);
          }
          lines = (char**)realloc(lines, size + sizeof(char*));
          if(lines)
          {
               lines[*count] = (char*)malloc(strlen(ptr) + 1);
               if(lines[*count])
               {
                    strcpy(lines[*count],ptr);
                    *count = *count + 1;
               }
          }
          ptr = strtok(NULL,seperator);
     }
     free(temp);
     return lines;
}
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Expert Comment

by:MadYugoslav
ID: 6268569
I think that my comment also can be improved but work.
Is it ?
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LVL 10

Expert Comment

by:makerp
ID: 6268726
to print out the values after calling simply

int count = 0;

char **retval = splitText(my_str,&count,"?")

for(int i=0;i<count;i++)
{
  printf("%s\n",retval[i])
}

then to free all of the values in the pointer array simply call this function passing the array and the count

i.e.

pm_free_ptr_2_ptr((void**)retval,count);

/* clean up a ** list of pointers */
void pm_free_ptr_2_ptr(void **ptr, int count)
{
     if(ptr)
     {    
          for(int i = 0;i < count;i++)
          {
               if(ptr[i])
               {
                    free(ptr[i]);
               }
          }
          free(ptr);
     }
}

to allocate each in a 100 bytes buffer simply replace

lines[*count] = (char*)malloc(strlen(ptr) + 1);
 with
lines[*count] = (char*)malloc(100);

although using just strcpy is dangerous now as your token may be greater then 100? so instead of

strcpy(lines[*count],ptr);
 use
strncpylines[*count],ptr,100);

paul

0
 
LVL 10

Expert Comment

by:makerp
ID: 6268730
strncpy(lines[*count],ptr,100);

whoops, missing (
0
 
LVL 1

Author Comment

by:Kitty__Kong
ID: 6269989
strcpy(pszBuffer[i*100], token)

is causing some warnings

D:\Programming\c_c++\strings\strings.c(19) : warning C4047: 'function' : 'char *' differs in levels of indirection from 'char '


D:\Programming\c_c++\strings\strings.c(19) : warning C4024: 'strcpy' : different types for formal and actual parameter 1
0
 

Expert Comment

by:wkmatt42
ID: 6270069
Try

strcpy(&pszBuffer[i*100], token)

or

strcpy(pszBuffer + i*100, token)
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