Thanks to OCD, I programed a new line remover for text files. Needs some work still.

**ImageJPEG** · 12-29-2017

So I've replaced '\r' and '\n' with '\0'. This, however, just fills up the file with 0s instead of just removing the contents all together. I would like to just fill the '\n' with nothing, not even zeros. No, the zeros don't show up on an average text editor, however, they do show as ^@ on vim and on a hex editor they show up as binary 0s.

The reason why I did this is because I've been creating SSH keys to log into my servers. When transferring the public keys via macOS or another *nix system, it would send the key as a one line text file.

Windows on the other hand did not. This annoyed me and I wanted to make something to remove all the new lines.

This is what I came up with.

Here's the source:

Code:

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


int main(int argc, const char *argv[]) {
    unsigned long long fileSize, programCounter;
    char *fileData;
    FILE *fp;
    
    fileSize = 0;
    fileData = NULL;
    fp = NULL;
    
    if(argc != 2) {
        fprintf(stderr, "Enter only one file, please.\n");
        return 1;
    }
    fp = fopen(argv[1], "r");
    if(fp == NULL) {
        fprintf(stderr, "Could not open file: %s.\n", argv[1]);
        return 1;
    }
    fseek(fp, 0L, SEEK_END);
    fileSize = ftell(fp);
    rewind(fp);
    
    fileData = malloc(fileSize);
    if(fileData == NULL) {
        fprintf(stderr, "Could not allocate memory.\n");
        return 1;
    }
    
    fread(fileData, fileSize, 1, fp);
    
    fclose(fp);
    
    for(programCounter = 0; programCounter < fileSize; programCounter++) {
        if(fileData[programCounter] == '\r')
            fileData[programCounter] = '\0';
        
        if(fileData[programCounter] == '\n')
            fileData[programCounter] = '\0';
    }
    
    fp = fopen(argv[1], "w");
    fwrite(fileData, fileSize, 1, fp);
    fclose(fp);
    
    free(fileData);
    
    return 0;
}

**Matticus** · 12-29-2017

You're reading and writing in binary, not text. In this context, '\0' does not behave as a string-terminating character. Hence it is printing the actual binary value of '\0'.

Incidentally, when using fread/fwrite, it is more appropriate to open files in binary mode ("rb", "wb").

Reading and writing your files as text (using fgets and fputs instead) might be more appropriate.

**john.c** · 12-29-2017

As a simple filter:

Code:

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

int main() {
    char line[1000];
    while (fgets(line, sizeof line, stdin) != NULL) {
        char *p;
        if ((p = strchr(line, '\r')) != NULL)
            *p = '\0';
        else if ((p = strchr(line, '\n')) != NULL)
            *p = '\0';
        fputs(line, stdout);
    }
    return 0;
}

Shorter:

Code:

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

int main() {
    char line[1000];
    while (fgets(line, sizeof line, stdin) != NULL) {
        line[strcspn(line, "\r\n")] = '\0';
        fputs(line, stdout);
    }
    return 0;
}

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Thanks to OCD, I programed a new line remover for text files. Needs some work still.

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