| OS | Man Page | Section | Hits |
|---|---|---|---|
| freebsd | catopen | 3 | 231 |
| opendarwin | catopen | 3 | 136 |
| mojave | catopen | 3 | 127 |
| redhat | catopen | 3 | 125 |
| linux | catopen | 3 | 121 |
| netbsd | catopen | 3 | 114 |
| opensolaris | catopen | 3c | 108 |
| ultrix | catopen | 3int | 108 |
| v7 | catopen | 3 | 107 |
| debian | catopen | 3 | 105 |
| sunos | catopen | 3c | 103 |
| osx | catopen | 3 | 103 |
| suse | catopen | 3 | 96 |
| hpux | catopen | 3c | 96 |
| osf1 | catopen | 3 | 96 |
| xfree86 | catopen | 3 | 95 |
| centos | catopen | 3 | 94 |
| posix | catopen | 3p | 74 |
| suse | catopen | 3p | 40 |
| centos | catopen | 3p | 36 |