Where is OPEN_MAX defined for Linux systems?

Question

OPEN_MAX is the constant that defines the maximum number of open files allowed for a single program.

According to Beginning Linux Programming 4^th

Answer 1

I suggest to use the magic of grep to find this constant on /usr/include:

grep -rn --col OPEN_MAX /usr/include

...
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/usr/include/stdio.h:159:   FOPEN_MAX   Minimum number of files that can be open at once.
...
...

Hope it helps you