isatty()
を使用 :
$ man isatty
ISATTY(3) Linux Programmer's Manual ISATTY(3)
NAME
isatty - does this descriptor refer to a terminal
SYNOPSIS
#include <unistd.h>
int isatty(int desc);
DESCRIPTION
returns 1 if desc is an open file descriptor connected to a terminal
and 0 otherwise.
stdout
以降 は常にファイル記述子 1 です。次のことができます:
if(isatty(1))
// stdout is a terminal
if (isatty (1))
fprintf (stdout, "Outputting to a terminal.");
else
fprintf (stdout, "Not outputting to a terminal.");