PUTC(3S-SVR4)       RISC/os Reference Manual        PUTC(3S-SVR4)



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

SYNOPSIS
     #include <stdio.h>

     int putc (int c, FILE *stream);

     int putchar (int c);

     int fputc (int c, FILE *stream);

     int putw (int w, FILE *stream);

DESCRIPTION
     putc writes c (converted to an unsigned char) onto the out-
     put stream [see intro(3)] at the position where the file
     pointer (if defined) is pointing, and advances the file
     pointer appropriately.  If the file cannot support position-
     ing requests, or stream was opened with append mode, the
     character is appended to the output stream.  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 argu-
     ment to a function.

     putw writes the word (i.e., integer) w to the output stream
     (where 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 align-
     ment in the file.

SEE ALSO
     exit(2), lseek(2), write(2), abort(3C), fclose(3S),
     ferror(3S), fopen(3S), fread(3S), printf(3S), puts(3S),
     setbuf(3S), stdio(3S).

DIAGNOSTICS
     On success, these functions (with the exception of putw)
     each return the value they have written.  putw returns fer-
     ror (stream).  On failure, they return the constant EOF.
     This result will occur, for example, if the file stream is
     not open for writing or if the output file cannot grow.

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.




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PUTC(3S-SVR4)       RISC/os Reference Manual        PUTC(3S-SVR4)



     Because of possible differences in word length and byte ord-
     ering, files written using putw are machine-dependent, and
     may not be read using getw on a different processor.

     Functions exist for all the above defined macros.  To get
     the function form, the macro name must be undefined (e.g.,
     #undef putc).
















































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