.TH PUTC 3S .UC .SH NAME putc, putchar, fputc, putw \- put character or word on a stream .SH SYNOPSIS .B #include .PP .B int putc(c, stream) .br .B char c; .br .SM .B FILE .B *stream; .PP .B putchar(c) .PP .B fputc(c, stream) .br .SM .B FILE .B *stream; .PP .B putw(w, stream) .br .SM .B FILE .B *stream; .SH DESCRIPTION .I Putc appends the character .I c to the named output .IR stream . It returns the character written. .PP .I Putchar(c) is defined as .I "putc(c, stdout)." .PP .I Fputc behaves like .I putc, but is a genuine function rather than a macro. It may be used to save on object text. .PP .I Putw appends word (i.e. .BR int ) .I w to the output .IR stream . It returns the word written. .I Putw neither assumes nor causes special alignment in the file. .PP The standard stream .I stdout is normally buffered if and only if the output does not refer to a terminal; this default may be changed by .IR setbuf (3S). The standard stream .I stderr is by default unbuffered unconditionally, but use of .I freopen (see .IR fopen (3S)) will cause it to become buffered; .IR setbuf , again, will set the state to whatever is desired. When an output stream is unbuffered information appears on the destination file or terminal as soon as written; when it is buffered many characters are saved up and written as a block. .I Fflush (see .IR fclose (3S)) may be used to force the block out early. .SH "SEE ALSO" fclose(3S), fopen(3S), fread(3S), getc(3S), printf(3S), puts(3S) .SH DIAGNOSTICS These functions return the constant .SM .B EOF upon error. Since this is a good integer, .IR ferror (3S) should be used to detect .I putw errors. .SH BUGS Because it is implemented as a macro, .I putc treats a .I stream argument with side effects improperly. In particular `putc(c, *f++);' doesn't work sensibly.