CODEWITHSUNDEEP
c
user3457200
user3457200

Reputation: 129

counting number of lines not working correctly through loop

I'm trying to count the number of lines of a wchar_t string on my C program using 2 methods: 1st method using a loop through the buffer counting "\n", the 2nd one is using wcstok() however I got only the 2nd method returning the correct lines number, the 1st one returns always 0: here is my full program code:

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

const wchar_t* ret2line_template = L"\n";

int get_lines_count1(wchar_t* w){
int count=0;
int i;
for(i=0;i<wcslen(w);i++)if((w[i]==ret2line_template[0]) && (w[i+1]==ret2line_template[1]))count++;
return count;
}
int get_lines_count2(wchar_t* w){
    int count=0;
    wcstok(w, ret2line_template);
    do{count++;}while(wcstok(0, ret2line_template));
    return count;
}

int main(){
const wchar_t* s = L"00\n11\n22\n33";
const wchar_t* w;
w = calloc(sizeof(wchar_t*), wcslen(s)+1);
wcscpy(w, s);
printf("lines count from get_lines_count1 = %d\n", get_lines_count1(w)); //this returns 0: incorrect value
printf("lines count from get_lines_count2 = %d\n", get_lines_count2(w)); //this returns 4: the correct value
getch();
}

so what's wrong with my get_lines_count1 function and its loop? how to fix that problem? please help.

Upvotes: 0

Views: 88

Answers (1)

WhozCraig
WhozCraig

Reputation: 66194

You're only incrementing count in the first function if you match on a newline followed by a null char.

This:

ret2line_template[1]

in your conditional expression is looking at the second wchar_t in this:

const wchar_t* ret2line_template = L"\n";

which is the zero terminator. None of the pairs of wchar_t's in your string match this, so the result is zero. Just look for a L'\n'. If there are chars left after the last one, add one more "line" to your count (the last one that has no L'\n' trailing.

Upvotes: 3

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