putc(S)                        6 January 1993                        putc(S)


 Name

    putc, putchar, fputc, putw - put character or word on a stream

 Syntax


    cc ... -lc


    #include <stdio.h>

    int putc (c, stream)
    int c;
    FILE *stream;

    int putchar (c)
    int c;

    int fputc (c, stream)
    int c;
    FILE *stream;

    int putw (w, stream)
    int w;
    FILE *stream;


 Description

    The putc macro writes the character c onto the output stream (at the
    position where the file pointer, if defined, is pointing).  putchar(c) is
    defined as putc(c, stdout).  putc and putchar are macros.

    fputc behaves like putc, but is a function rather than a macro.  fputc
    runs more slowly than putc, but it takes less space per invocation and
    its name can be passed as an argument to a function.

    putw writes the word (that is, integer) w to the output stream (at the
    position at which the file pointer, if defined, is pointing).  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.

 Diagnostics

    On success, these functions (with the exception of putw) each return the
    value they have written.  (putw returns ferror (stream).)  On failure,
    they return the constant EOF.  This occurs if the file stream is not open
    for writing or if the output file cannot grow.  Because EOF is a valid
    integer, ferror(S) should be used to detect putw errors.

 Notes

    Because it is implemented as a macro, putc evaluates a stream argument
    more than once.  In particular, putc(c,*f++) doesn't work sensibly.
    fputc should be used instead.

    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.

 See also

    fclose(S), ferror(S), fopen(S), fread(S), printf(S), puts(S), setbuf(S),
    stdio(S)

 Standards conformance

    fputc, putc and putchar are conformant with:
    AT&T SVID Issue 2;
    X/Open Portability Guide, Issue 3, 1989;
    ANSI X3.159-1989 Programming Language -- C;
    Intel386 Binary Compatibility Specification, Edition 2 (iBCSe2);
    IEEE POSIX Std 1003.1-1990 System Application Program Interface (API) [C
    Language] (ISO/IEC 9945-1); and NIST FIPS 151-1.

    putw is conformant with:
    AT&T SVID Issue 2;
    X/Open Portability Guide, Issue 3, 1989;
    Intel386 Binary Compatibility Specification, Edition 2 (iBCSe2).