clearerr_unlocked - Linux

Overview

The clearerr_unlocked() function clears the end-of-file (EOF) indicator and error indicators for a given FILE stream, allowing subsequent read/write operations to continue without errors. It is designed to operate on unlocked file streams.

Syntax

#include <stdio.h>

void clearerr_unlocked(FILE *stream);

Options/Flags

None

Examples

Simple Example: Clear errors on a file stream.

#include <stdio.h>

int main() {
    FILE *file = fopen("myfile.txt", "r");

    // Clear any errors
    clearerr_unlocked(file);

    // Continue reading or writing to the file

    return 0;
}

Example with Error Handling: Handle errors and clear them to continue reading.

#include <stdio.h>
#include <errno.h>

int main() {
    FILE *file = fopen("myfile.txt", "r");
    int c;

    while ((c = getc_unlocked(file)) != EOF) {
        // Process character here
        if (ferror(file)) {
            // Error occurred, clear it and continue
            clearerr_unlocked(file);
            continue;
        }
    }

    return 0;
}

Common Issues

• Ensure that the file stream is unlocked before using clearerr_unlocked() to avoid race conditions.
• Repeated errors on a file stream may indicate a more severe underlying issue that needs to be addressed.

Integration

clearerr_unlocked() can be used in conjunction with other file-handling functions to manipulate and clear errors on FILE streams. It is particularly useful in multi-threaded applications to ensure that errors are properly cleared and handled.

Related Commands

• clearerr(): Clears errors on a file stream.
• ferror(): Checks for errors on a file stream.
• fileno_unlocked(): Obtains the file descriptor associated with a file stream.