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.