put
put(fid, str)
This function writes the characters given by str to the file identified by fid, which must be a return value from a previous call to open. The file associated with fid must have been opened for writing.
• put does not add any newline characters after str. If linefeeds are desired, they must be given as part of the string. The output to the stream is buffered; flush can be used to force characters to be written.
• put returns the number of characters written or -1 on failure (such as an attempt to write to a file identifier opened exclusively for reading).