c/io/gets

@1@ Reads stdin into the character array pointed to by until a newline character is found or end-of-file occurs. A null character is written immediately after the last character read into the array. The newline character is discarded but not stored in the buffer.

@2@ Reads characters from stdin until a newline is found or end-of-file occurs. Writes only at most characters into the array pointed to by, and always writes the terminating null character (unless str is a null pointer). The newline character, if found, is discarded and does not count toward the number of characters written to the buffer.
 * The following errors are detected at runtime and call the currently installed constraint handler function:
 * is zero
 * is greater than
 * is a null pointer
 * endline or eof not encountered after storing characters to the buffer.
 * In any case, first finishes reading and discarding the characters from stdin until new-line character, end-of-file condition, or read error before calling the constraint handler.

Return value
on success, a null pointer on failure.

If the failure has been caused by end of file condition, additionally sets the eof indicator (see feof) on stdin. If the failure has been caused by some other error, sets the error indicator (see ferror) on stdin.