fputs_unlocked - Linux
Overview
fputs_unlocked writes a string to a stream, without the file locking performed by fputs. Use fputs_unlocked for better performance in multithreaded programs.
Syntax
#include <stdio.h>
int fputs_unlocked(const char *s, FILE *stream);
Options/Flags
None.
Examples
#include <stdio.h>
#include <pthread.h>
void *thread_func(void *arg)
{
FILE *f = (FILE *)arg;
fputs_unlocked("Hello from a thread!\n", f);
return NULL;
}
int main()
{
FILE *f = fopen("output.txt", "w");
pthread_t thread;
pthread_create(&thread, NULL, thread_func, f);
fputs_unlocked("Hello from the main thread!\n", f);
pthread_join(thread, NULL);
fclose(f);
return 0;
}
Common Issues
- Buffer overflow: The string passed to fputs_unlocked must fit within the stream’s output buffer. If it doesn’t, undefined behavior may occur.
- Concurrency errors: fputs_unlocked is not thread-safe. If multiple threads are writing to the same stream concurrently, data corruption can occur.
Integration
fputs_unlocked can be combined with other stream manipulation functions, such as fseek, ftell, and fclose, to perform advanced file I/O operations.
Related Commands
- fputs: File locking version of fputs_unlocked
- fprintf: Formatted output to a stream
- fwrite: Write raw data to a stream