Sun Java System Web Server 7.0 Update 4 NSAPI Developer's Guide

system_fwrite_atomic() Function

The system_fwrite_atomic function writes a specified number of bytes from a specified buffer into a specified file. This function also locks the file prior to performing the write, and then unlocks it when done, thereby avoiding interference between simultaneous write actions. Before system_fwrite_atomic can be used, you must open the file using any of the system_fopen functions except system_fopenRO.


int system_fwrite_atomic(SYS_FILE fd, char *buf, int sz);

Return Values

The constant IO_OKAY if the write/lock succeeds, or the constant IO_ERROR if the write/lock fails.


SYS_FILE fd is the platform-independent file descriptor.

char *buf is the buffer containing the bytes to be written.

int sz is the number of bytes to write to the file.


SYS_FILE logfd;
char *logmsg = "An error occurred.";
system_fwrite_atomic(logfd, logmsg, strlen(logmsg));

See Also

system_errmsg() Function, system_fopenRO() Function, system_fopenRW() Function, system_fopenWA() Function, system_lseek() Function, system_fread() Function, system_fwrite() Function, system_flock() Function, system_ulock() Function, system_fclose() Function