| OS | Man Page | Section | Hits |
|---|---|---|---|
| freebsd | catopen | 3 | 971 |
| mojave | catopen | 3 | 725 |
| redhat | catopen | 3 | 714 |
| hpux | catopen | 3c | 683 |
| opendarwin | catopen | 3 | 653 |
| suse | catopen | 3 | 643 |
| opensolaris | catopen | 3c | 622 |
| linux | catopen | 3 | 609 |
| osx | catopen | 3 | 606 |
| centos | catopen | 3 | 600 |
| xfree86 | catopen | 3 | 570 |
| netbsd | catopen | 3 | 568 |
| v7 | catopen | 3 | 559 |
| sunos | catopen | 3c | 554 |
| debian | catopen | 3 | 536 |
| ultrix | catopen | 3int | 498 |
| posix | catopen | 3p | 457 |
| osf1 | catopen | 3 | 429 |
| suse | catopen | 3p | 379 |
| centos | catopen | 3p | 379 |