unistd.h#
- _exit
- alarm
- chdir
- close
- crypt
- dup
- exec
- fchdir
- fchown
- fork
- fsync
- ftruncate
- getcwd
- getegid
- geteuid
- getgid
- getgroups
- getlogin
- getopt
- getpgid
- getpgrp
- getpid
- getppid
- getsid
- getuid
- isatty
- link
- lseek
- pipe
- read
- rmdir
- setegid
- seteuid
- setgid
- setpgid
- setsid
- setuid
- sleep
- sync
- tcgetpgrp
- tcsetpgrp
- truncate
- ttyname
- unlink
- usleep
- vfork
- write