16.
Explanation
Create, open, and close files in a program using functions from the standard input/output library. The key functions for file operations are fopen(), fclose(), and various functions for reading and writing to files
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Create a File: To create a new file, you can use the fopen() function with the "w" mode (write mode). If the file already exists, it will be truncated; if it doesn't exist, a new file will be created.
#include <stdio.h>
int main() {
FILE *file;
file = fopen("example.txt", "w");
if (file == NULL) {
printf("Failed to create/open the file.\n");
return 1;
}
// Perform file operations here
fclose(file); // Close the file
return 0;
}
2. Open a File: To open an existing file for reading or writing, you can use fopen() with different modes such as "r" (read), "w" (write), "a" (append), and more.
FILE *file;
file = fopen("existing_file.txt", "r"); // Open for reading
if (file == NULL) {
printf("Failed to open the file.\n");
return 1;
}
// Perform file operations here
fclose(file); // Close the file
Close a File: Always remember to close a file using the fclose() function when you're done with it. This ensures that any changes are saved, and resources are released.
FILE *file;
file = fopen("example.txt", "w");
if (file == NULL) {
printf("Failed to create/open the file.\n");
return 1;
}
// Perform file operations here
fclose(file); // Close the file
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Writing to a File: To write data to a file, you can use functions like fprintf(), fputc(), and fputs(). Here's an example using fprintf() to write text to a file.
FILE *file;
file = fopen("output.txt", "w");
if (file == NULL) {
printf("Failed to create/open the file.\n");
return 1;
}
fprintf(file, "Hello, this is some text.\n");
fclose(file); // Close the file
Other functions like ‘fputc()’ and ‘fputs()’ can be used for character-wise and string-wise output, respectively.