Finding out that the output of my program is redirected into a file

Question

I want to know if it is posible in linux and C to find out that my programs output is redirected to a file. I want to format the output human readable when it is printed on stdout $ ./myprogram and like csv when it is redirected to a file $ ./myprogram >> data.csv

is it posible?

Interesting question. Maybe with the argv/argc from main()? – Burkhard Feb 07 '13 at 06:15 — Burkhard, Feb 07 '13 at 06:15

score 10 · Accepted Answer · answered Feb 07 '13 at 06:16

10

You can use the isatty function for that:

if (isatty(STDOUT_FILENO))
{
    /* Standard out is an interactive terminal */
}
else
{
    /* Standard out is something else (pipe, file redirect, etc.) */
}

answered Feb 07 '13 at 06:16

Some programmer dude

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thanks, `if(isatty(fileno(stdout))){is a terminal}else{is a file};` :) – microo8 Feb 07 '13 at 06:22

Finding out that the output of my program is redirected into a file

1 Answers1