linecheck.c

/*
 * Copyright (C) 2077 The Legacy Code Source Project
 *
 * Licensed under the WTFPL License, Version 2.0 (the "License");
 * Everyone is permitted to copy and distribute verbatim or
 * modified copies of this license document, and changing it is allowed
 * as long  as the name is changed.
 *      0. You just DO WHAT THE FUCK YOU WANT TO.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */



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

// Compile-time OS detection
#ifdef _WIN32
    #define COMPILED_OS "Windows"
#else
    #define COMPILED_OS "Linux/Unix"
#endif

void check_line_endings(const char *filename) {
    FILE *fp = fopen(filename, "rb"); // Open in binary mode to read raw bytes
    if (!fp) {
        perror("Error opening file");
        return;
    }

    int ch, prev = -1;
    int count_lf = 0;      // \n (Unix/Linux)
    int count_cr = 0;      // \r (Old Mac)
    int count_crlf = 0;    // \r\n (Windows)

    while ((ch = fgetc(fp)) != EOF) {
        if (ch == '\n') {
            count_lf++;
            if (prev == '\r') {
                count_crlf++;
            }
        }
        if (ch == '\r') {
            count_cr++;
        }
        prev = ch;
    }
    fclose(fp);

    int standalone_lf = count_lf - count_crlf; // LF without preceding CR
    int standalone_cr = count_cr - count_crlf; // CR without following LF

    printf("\n--- Analysis for: %s ---\n", filename);
    printf("Total LF (\\n) chars     : %d\n", count_lf);
    printf("Total CR (\\r) chars     : %d\n", count_cr);
    printf("CRLF (\\r\\n) pairs       : %d\n", count_crlf);

    // Conclusion logic
    if (count_crlf > 0 && standalone_lf == 0 && standalone_cr == 0) {
        printf(">>> Conclusion: WINDOWS (CRLF) line endings.\n");
    }
    else if (count_lf > 0 && count_crlf == 0 && count_cr == 0) {
        printf(">>> Conclusion: LINUX/UNIX (LF) line endings.\n");
    }
    else if (count_cr > 0 && count_lf == 0 && count_crlf == 0) {
        printf(">>> Conclusion: OLD MAC (CR) line endings.\n");
    }
    else {
        printf(">>> Conclusion: MIXED line endings!\n");
        if (standalone_lf > 0) printf("    - %d standalone LF (Linux style)\n", standalone_lf);
        if (standalone_cr > 0) printf("    - %d standalone CR (Old Mac style)\n", standalone_cr);
        if (count_crlf > 0)    printf("    - %d CRLF (Windows style)\n", count_crlf);
    }
}

int main(int argc, char *argv[]) {
    printf("This program was compiled for: %s\n", COMPILED_OS);
    printf("Currently running on         : ");
    #ifdef _WIN32
        printf("Windows\n");
    #else
        printf("Linux/Unix\n");
    #endif

    if (argc < 2) {
        fprintf(stderr, "\nUsage: %s <filename>\n", argv[0]);
        fprintf(stderr, "Example: %s main.c\n", argv[0]);
        return 1;
    }

    check_line_endings(argv[1]);
    return 0;
}