CODEWITHSUNDEEP
c
friends
friends

Reputation: 639

stange output with split a string from file by a space

counter.txt

1 2 3
4 5 6
7 8 9

void  split_str(char line_str[10]) {

    int i, j;
    i=0;

    char  sub_str[10][20];   
    char  *token;

    token = strtok(line_str," ");     

    while (token != NULL) {
        strcpy(sub_str[i], token);   
        i=i+1;
        token=strtok(NULL," ");   
    }   

    for (j=0; j<=i; j++)
        printf("The char is %s\n",sub_str[j]);


} //split_str

void main() {

    file_ptr=fopen("counter.txt", "r");

    while ( fgets ( line, sizeof line, file_ptr ) != NULL ) { 
        split_str(line);
    }      

    fclose ( file_ptr );
}

Result:
The char is 1
The char is 2
The char is 3

The char is 。" //a space with double quota
The char is 4
The char is 5
The char is 6

The char is 。"
The char is 7
The char is 8
The char is 9
The char is 。"

。is space, this web site trimmed

there are some char " "" a space with double quota that i unexpected, what is that? thanks

Upvotes: 0

Views: 165

Answers (1)

Eli Bendersky
Eli Bendersky

Reputation: 273884

What you see is garbage data in sub_str because this code is incorrect:

while (token != NULL) {
    strcpy(sub_str[i], token);   
    i=i+1;
    token=strtok(NULL," ");   
}   

for (j=0; j<=i; j++)
    printf("%s\n",sub_str[j]);

The for loop should run until j < i here. This is because at sub_str[i] you just have some dummy value, since after i=i+1 you exit the while loop on the NULL token.

Try to simulate it "in your head" or run in a debugger to see the problem in action.

Upvotes: 1

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