Write Data to File Function

Documentation for Function: write_into_file

Function Signature

int write_into_file(char *filepath, int *ps, int *pe);

Purpose

The write_into_file function is designed to write data into a specific file. The data to be written is provided through pointers to two integer values (ps and pe).

Parameters

• filepath (char*):

  • Description: A string representing the path to the file where data should be written.
  • Expected Value: A null-terminated string.
  • Usage: Used to open the file at the specified path for writing data.

• ps (int*):

  • Description: Pointer to the start integer value.
  • Expected Value: A valid pointer to an integer.
  • Usage: The integer value pointed to by ps is part of the data written into the file.

• pe (int*):

  • Description: Pointer to the end integer value.
  • Expected Value: A valid pointer to an integer.
  • Usage: The integer value pointed to by pe is part of the data written into the file.

Return Type

• int
  • Returns 0 on successful write operation.
  • Returns -1 if there is an error during the file operation (such as failure to open the file or write data).

Description

• This function attempts to open the file specified by filepath in write mode.
• It writes the integer values pointed to by ps and pe into the file.
• If any step in this process fails (such as the file cannot be opened), the function returns -1.
• If successful, the function returns 0.

Example Usage

int main() {
    char *filepath = "output.txt";
    int start_value = 10;
    int end_value = 20;
    
    int result = write_into_file(filepath, &start_value, &end_value);
    if (result == 0) {
        printf("Data written successfully.\n");
    } else {
        printf("Failed to write data.\n");
    }
    
    return 0;
}

Inline Comments

Below is the function with detailed inline comments explaining the key steps:

#include 

int write_into_file(char *filepath, int *ps, int *pe) {
    FILE *file;

    // Attempt to open the file in write mode
    file = fopen(filepath, "w");
    if (file == NULL) {
        // Return -1 if file cannot be opened
        return -1;
    }

    // Write the start value to the file
    if (fprintf(file, "%d\n", *ps) < 0) {
        // Close the file if writing failed
        fclose(file);
        return -1;
    }

    // Write the end value to the file
    if (fprintf(file, "%d\n", *pe) < 0) {
        // Close the file if writing failed
        fclose(file);
        return -1;
    }

    // Close the file after writing
    fclose(file);

    // Return 0 to indicate success
    return 0;
}

Detailed Explanation

1. Opening the File:

   • The function uses fopen to open the file specified by filepath in write mode ("w").
   • If fopen returns NULL, the file could not be opened (possibly due to permissions or a non-existent path), and the function returns -1.

2. Writing Data:

   • The function uses fprintf to write the integer values pointed to by ps and pe into the file.
   • Each fprintf call writes an integer followed by a newline character (\n).
   • If fprintf fails (returns a negative value), the file is closed using fclose, and the function returns -1.

3. Closing the File:

   • After successfully writing the data, the function closes the file using fclose.
   • The function returns 0 to indicate that the operation was successful.