PUTC(3S)             INTERACTIVE UNIX System             PUTC(3S)



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

          SYNOPSIS
               #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 function 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 argu-
               ment to a function.

               Putw writes the word (i.e., 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.

          SEE ALSO
               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 will occur if the file stream is not open for writing
               or if the output file cannot grow.  Because EOF is a valid
               integer, ferror(3S) should be used to detect putw errors.

          CAVEATS
               Because it is implemented as a macro, putc evaluates a


          Rev. C Software Development Set                            Page 1

          PUTC(3S)             INTERACTIVE UNIX System             PUTC(3S)



               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 ord-
               ering, files written using putw are machine-dependent, and
               may not be read using getw on a different processor.


















































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