stdio(3s)                  DG/UX 4.30                   stdio(3s)



     NAME
          stdio - standard buffered input/output package

     SYNOPSIS
          #include <stdio.h>

          FILE *stdin, *stdout, *stderr;

     DESCRIPTION
          The 3S entries in this manual constitute an efficient,
          user-level I/O buffering scheme.  The in-line macros
          getc(3S) and putc(3S) handle characters quickly.  The macros
          getchar and putchar, and the higher-level routines fgetc,
          fgets, fprintf, fputc, fputs, fread, fscanf, fwrite, gets,
          getw, printf, puts, putw, and scanf all use or act as if
          they use getc and putc; they can be freely intermixed.

          A file with associated buffering is called a stream and is
          declared to be a pointer to a defined type FILE.  Fopen(3S)
          creates certain descriptive data for a stream and returns a
          pointer to designate the stream in all further transactions.
          Normally, there are three open streams with constant
          pointers declared in the <stdio.h> header file and
          associated with the standard open files:

               stdin     standard input file
               stdout    standard output file
               stderr    standard error file

          A constant NULL (0) designates a nonexistent pointer.

          An integer-constant EOF (-1) is returned upon end-of-file or
          error by most integer functions that deal with streams (see
          the individual descriptions for details).

          An integer constant BUFSIZ specifies the size of the buffers
          used by the particular implementation.

          Any program that uses this package must include the header
          file of pertinent macro definitions, as follows:

               #include <stdio.h>

          The functions and constants for all 3S entries in this
          manual are declared in the header file and need no further
          declaration.  The constants and the following "functions"
          are implemented as macros. Don't redeclare these names:
          getc, getchar, putc, putchar, ferror, feof, clearerr, and
          fileno.

     SEE ALSO
          open(2), close(2), lseek(2), pipe(2), read(2), write(2),



     Licensed material--property of copyright holder(s)         Page 1

     stdio(3s)                  DG/UX 4.30                   stdio(3s)



          ctermid(3S), cuserid(3S), fclose(3S), ferror(3S), fopen(3S),
          fread(3S), fseek(3S), getc(3S), gets(3S), popen(3S),
          printf(3S), putc(3S), puts(3S), scanf(3S), setbuf(3S),
          system(3S), tmpfile(3S), tmpnam(3S), ungetc(3S).

     DIAGNOSTICS
          Invalid stream pointers will usually cause problems,
          possibly including program termination.  The description for
          each function lists its possible error conditions.














































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