#include <lcio.h> int isatty(int fn);The syntax for the POSIX implementation is
#include <sys/types.h> #include <unistd.h> int isatty(int fn);
isatty
tests whether the file associated with file number fn
is an interactive terminal. isatty
returns a non-zero value if the
file number represents a TSO terminal, a CMS terminal, or an OpenEdition
terminal. isatty
returns 0 for the DDname SYSTERM when called under MVS
batch.
#include <lcio.h> #include <stdio.h> double point[40]; main() { FILE *f; int index = 0; double sum = 0.0; double avg ; int nopoints; int fn =0; /* If stdin is the terminal, (fileno(stdin) is always 0). */ if (isatty(fn)) /* Tell user to enter data points - max. = 39. */ puts("Enter data points (-1 to indicate end of list)."); for(;;){ /* Read number; check for end of file. */ if (scanf("%le", &point[index]) <= 0) break; if (point[index] == -1) break; sum += point[index]; ++index; } nopoints = index; avg = sum / nopoints; printf("%d points read.n", nopoints); printf("%f = average.n", avg); }
fattr
, fstat
, fterm
Copyright (c) 1998 SAS Institute Inc. Cary, NC, USA. All rights reserved.