Checking output redirection in PHP?

Question

PHP

How to check if stdout is redirected or not?
The bottom line is, there is a color output. In the console, it is good and colorful, but not in a text file.
If the output is redirected to a file, I want to remove the coloring. How to check where the output goes?

Answer 1

man 3 isatty

Answer 2

not sure if it will work, but came up with the idea of ​​parsing the command line (can be found in /proc/PID/cmdline on redhat linux)