This chapter is from the book
This chapter is from the book
This chapter is from the book
This chapter is from the book
3.8 write Function
Data is written to an open file with the write function.
#include <unistd.h>
ssize_t write(int filedes,
const void *buff, size_t
nbytes);
Returns: number of bytes
written if OK, -1 on error
The return value is usually equal to the nbytes argument, otherwise an error has occurred. A common cause for a write error is either filling up a disk or exceeding the file size limit for a given process (Section 7.11 and Exercise 10.11).
For a regular file, the write starts at the file's current offset. If the O_APPEND option was specified in the open, the file's offset is set to the current end of file before each write operation. After a successful write, the file's offset is incremented by the number of bytes actually written.