strtok problem

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PHP Code:

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/ Complete the program to count the number of words in the sentence an$
        // print each word separately, along with length of each word.

        // If line = "Arizona is hot", your output should be
        // Word 1: Arizona      Length = 7
        // Word 2: is           Length = 2
        // Word 3: hot          Length = 3
char *ptr;

        ptr= strtok(line,",");
printf("word:%s  length:%d \n\n",ptr,strlen(ptr));
        ptr=strtok(NULL,",");
printf("word:%s length:%d \n\n",ptr,strlen(ptr)); 


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for the second time i use a strtok i get a segmentation fault why is that?

what is line?

Compare ptr to NULL after you call strtok(). It's possibly failing because there's nothing left after you look for the first ','.

Code:

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#include <stdio.h>
#include <string.h>

// This function takes a character and a string
// as input and computes if the character is in
// the string or not.  Returns 1 if yes, 0 otherwise.
int  is_char_in_string(char c, char *s)
{
        while (*s != '\0')
        {
                if (c == *s) return 1;
                s++;
        }
        return 0;
}
main()
{
        char line[255];
        char delim[10] = " .,;!?";    // set of delimiting characters that can$
        int i;
        int length;

        // Get a line from user as input
        printf("Enter a sentence: ");
        gets(line);

        // The line before we replace the delimiting characters with 0.
        length = strlen(line);
        for(i=0;i<length; ++i)
        {
                printf ("%3c ", line[i]);
        }
        printf("\n\n");


 length = strlen(line);
        //Replace delimiting characters with '\0'.
        for(i=0;i<length; ++i)
        {
                if (is_char_in_string(line[i], delim))
                        line[i] = '\0';
        }
 // The line after we replace delimiting characters with 0.
        for(i=0;i<length; ++i)
        {
                printf ("%3c ", line[i]);
        }
        printf("\n\n");
        // Printing the line as integers so that we can see that space is
        // replaced with 0.
        for(i=0;i<length; ++i)
        {
                printf ("%3d ", line[i]);
        }
  printf("\n\n");


        // Complete the program to count the number of words in the sentence an$
        // print each word separately, along with length of each word.

        // If line = "Arizona is hot", your output should be
        // Word 1: Arizona      Length = 7
        // Word 2: is          Length = 2
        // Word 3: hot          Length = 3

char *ptr;

        ptr= strtok(line,",");
        if(ptr != NULL)
printf("word:%s  length:%d \n\n",ptr,strlen(ptr));

        ptr= strtok(' ',",");
printf("word:%s  length:%d \n\n",ptr,strlen(ptr));

       
}[

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here is the rest of the code what do you guys think is wrong.

Same thing I said was wrong last time.

do you mean
strcmp(ptr,NULL)

Code:

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ptr= strtok(' ',",");

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Add a check for NULL after this....

And change it back to:

Code:

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ptr= strtok(NULL,",");

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http://faq.cprogramming.com/cgi-bin/...&id=1043284351

PHP Code:

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   ptr= strtok(NULL,",");
        if(ptr != NULL)
printf("word:%s  length:%d \n\n",ptr,strlen(ptr));

        ptr= strtok(NULL,",");
        if(ptr != NULL)
printf("word:%s  length:%d \n\n",ptr,strlen(ptr));


}
                          


Enter a sentence: arizona is hot
  a   r   i   z   o   n   a       i   s       h   o   t

  a   r   i   z   o   n   a      i   s      h   o   t

 97 114 105 122 111 110  97   0 105 115   0 104 111 116

word:arizona  length:7 


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why is it not printing the other stuff, i thought for ther second time i call the strtok it starts at "is".

you have put \0 instead of space - for any standard C-string function it means - string ended here... so your string contains only "arizona" nothing more could be found using stndard C-functions...

so how can i fix that?

Quote:

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Originally Posted by rambos

so how can i fix that?

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1. do not put \0 into your string before calling strtok
2. write your own function that knows how to handle the string with \0 inside

is there a way to undo the \0 other than just erasing the code from before? in other words but it back as one of the deliminating characters.

Quote:

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is there a way to undo the \0 other than just erasing the code from before? in other words but it back as one of the deliminating characters.

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yes... you have original length of the string - walk along and replace \0 with char of your choice...

Code:

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PHP Code:

       

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for (line[i] ='\0')
{
 line[i]= delim[0];
} 




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i wrote this before your last post in hopes that it would change them to space but only gave me a bunch of errors when i compiled it.

word-count.c: In function `main':
word-count.c:71: error: syntax error before ')' token
word-count.c: At top level:
word-count.c:79: error: conflicting types for 'ptr'
word-count.c:77: error: previous declaration of 'ptr' was here
word-count.c:79: error: `line' undeclared here (not in a function)
word-count.c:79: warning: initialization makes integer from pointer without a cast
word-count.c:79: error: initializer element is not constant
word-count.c:79: warning: data definition has no type or storage class
word-count.c:81: error: syntax error before string constant
word-count.c:83: error: redefinition of 'ptr'
word-count.c:79: error: previous definition of 'ptr' was here
word-count.c:83: error: redefinition of 'ptr'
word-count.c:79: error: previous definition of 'ptr' was here
word-count.c:83: warning: initialization makes integer from pointer without a cast
word-count.c:83: error: initializer element is not constant
word-count.c:83: warning: data definition has no type or storage class
word-count.c:84: error: syntax error before "if"
word-count.c:87: error: redefinition of 'ptr'
word-count.c:83: error: previous definition of 'ptr' was here
word-count.c:87: error: redefinition of 'ptr'
word-count.c:79: error: previous definition of 'ptr' was here
word-count.c:87: warning: initialization makes integer from pointer without a cast
word-count.c:87: error: initializer element is not constant
word-count.c:87: warning: data definition has no type or storage class
word-count.c:88: error: syntax error before "if"
word-count.c:91: error: redefinition of 'ptr'
word-count.c:87: error: previous definition of 'ptr' was here
word-count.c:91: error: redefinition of 'ptr'
word-count.c:79: error: previous definition of 'ptr' was here
word-count.c:91: warning: initialization makes integer from pointer without a cast
word-count.c:91: error: initializer element is not constant
word-count.c:91: warning: data definition has no type or storage class
word-count.c:92: error: syntax error before "if"