Why the fwrite libc function is faster than the syscall write function?

Question

After providing the same program which reads a random generated input file and echoes the same string it read to an output. The only difference is that on one side I\'m providin

Answer 1

You can also disable buffering with setbuf() function. When the buffering is disabled, fwrite() will be as slow as write() if not slower.

More information on this subject can be found there: http://www.gnu.org/s/libc/manual/html_node/Controlling-Buffering.html