1 executable program or shell command (1 eeeeexecutable)
3 library (library like mountain high 3)
locate man3|grep gz|grep -v 'X11R6'|grep -v 'de'|grep -v 'ko'|grep -v 'pl
4 device (eat device will die 4)
man 4 null
man 4 tty
5 files (5 dance on file)
8 system program (only the root will be rich

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man 3 mkfifo
man 3 mkfifo
man -a mkfifo
man -a -Pless mkfifo
man -a -Pmore mkfifo
man -d ln
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less /etc/man.config