CODEWITHSUNDEEP
c
Steven Liu
Steven Liu

Reputation: 169

Find instance of different character in a file

In this program, I want to print out the instance of different characters in a file. The output will contain three variable, the number of occurrence, the hex of the letter, and the letter itself. Can someone help me with this? I am stuck!

 Results of program should be something like this:
 10 instance  of character 0x4s (O)
 10 instance  of character 0x51 (W)
 10 instance  of character 0x51 (Y)
 2 instances of character 0x65 (a)
 18 instances of character 0x67 (c)
 16 instances of character 0x81 (d)


//here is my program. 
#include <stdio.h>
#include <stdlib.h> 
#include <string.h>

const char FILE_NAME[] = "input.txt";


int main(argc, *argv[]) {

    char temp;   
     char count[255];

FILE *in_file;   
int ch;

fp = fopen(FILE_NAME, "r");
if (in_file == NULL) {
    printf("Can not open %s \n", FILE_NAME);
    exit(0);
}

while (!feof(fp)) {

    ch = fgetc(fp);

if(strchr(count, ch)!= NULL)
{

}

}
printf("%d instance of character (%c)", count);


fclose(in_file);
return (0);
}

Upvotes: 0

Views: 505

Answers (2)

halfelf
halfelf

Reputation: 10107

Here's what you want (based on your code, with many comments by me):

#include <stdio.h>
#include <stdlib.h> 
#include <string.h>
#include <ctype.h>  // you need this to use isupper() and islower()

const char FILE_NAME[] = "input.txt";

int main(int argc,char *argv[]) {
    char temp;   
    unsigned count[52] = {0};  // An array to store 52 kinds of chars
    FILE *fp;   
    int i;

    fp = fopen(FILE_NAME, "r");
    if (fp == NULL) {
        printf("Can not open %s \n", FILE_NAME);
        exit(0);
    }

    while((temp = fgetc(fp)) != EOF) {   // use this to detect eof
        if(isupper(temp))
            count[26+(temp-'A')]++;   // capital letters count stored in 26-51
        if(islower(temp))
            count[temp-'a']++;        // lower letters count stored in 0-25
    }
    fclose(fp);  // When you don't need it anymore, close it immediately.

    for(i = 0; i < 26; i++)
        if(count[i])
            printf("%d instance of character 0x%x (%c)\n", count[i], 'a'+i, 'a'+i);
    for(; i < 52; i++)
        if(count[i])
            printf("%d instance of character 0x%x (%c)\n", count[i], 'A'+i-26, 'A'+i-26);
    return (0);
}

Upvotes: 1

unwind
unwind

Reputation: 399793

Your array count is not a string, so using strchr() on it is not a good idea. Also, it's of type char, so it has very limited range for larger files.

You should probably use something like unsigned long count[256]. Make sure to initialize the counts to 0 before starting.

Also, don't use feof(). Just loop calling fgetc() until the returned character (which, correctly, has type int) is EOF. Cast it to something positive before using it to index into count for the increment.

Upvotes: 0

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