putc, putchar, fputc, putw - put character or word on a stream
int putc(c, stream)
int fputc(c, stream)
int putw(w, stream)
putc() writes the character c onto the standard I/O output stream
stream (at the position where the file pointer, if defined, is point-
ing). It returns the character written.
putchar(c) is defined as putc(c, stdout). putc() and putchar() are
fputc() behaves like putc(), but is a function rather than a macro.
fputc() runs more slowly than putc(), but it takes less space per invo-
cation and its name can be passed as an argument to a function.
putw() writes the C int (word) w to the standard I/O output stream
stream (at the position of the file pointer, if defined). The size of
a word is the size of an integer and varies from machine to machine.
putw() neither assumes nor causes special alignment in the file.
Output streams are by default buffered if the output refers to a file
and line-buffered if the output refers to a terminal. When an output
stream is unbuffered, information is queued for writing on the destina-
tion file or terminal as soon as written; when it is buffered, many
characters are saved up and written as a block. When it is line-
buffered, each line of output is queued for writing on the destination
terminal as soon as the line is completed (that is, as soon as a NEW-
LINE character is written or terminal input is requested). setbuf(3V),
setbuffer(), or setvbuf() may be used to change the stream's buffering
fclose(3V), ferror(3V), fopen(3V), fread(3S), getc(3V), printf(3V),
On success, putc(), fputc(), and putchar() return the value that was
written. On error, those functions return the constant EOF. putw()
returns ferror(stream), so that it returns 0 on success and 1 on fail-
Because it is implemented as a macro, putc() treats a stream argument
with side effects improperly. In particular, putc(c, *f++); does not
work sensibly. fputc() should be used instead.
Errors can occur long after the call to putc().
Because of possible differences in word length and byte ordering, files
written using putw() are machine-dependent, and may not be read using
getw() on a different processor.
10 October 1987 PUTC(3S)