unistd.hΒΆ _exit alarm chdir close crypt dup exec fork fsync ftruncate getcwd getegid gethostid gethostname getopt getpgid getpgrp getpid getppid getsid getuid isatty link lseek nice pause pipe read readlink rmdir setpgid setpgrp setsid sleep sysconf tcgetpgrp tcsetpgrp truncate unlink usleep vfork write