API Summary

 #include <sys/types.h>     #include <unistd.h>         #include <sys/wait.h>     #include <signal.h>     pid_t  fork  ( void );     pid_t  wait  ( int *status );     pid_t  waitpid  ( pid_t pid, int *status, int options );     sighandler_t  signal  ( int signum, sighandler_t handler );     int  pause  ( void );     int  kill  ( pid_t pid, int sig_num );     int  raise  ( int sig_num );     int  execl  ( const char *path, const char *arg, ... );     int  execlp  ( const char *path, const char *arg, ... );     int  execle  ( const char *path, const char *arg, ...,                    char * const envp[] );     int  execv  ( const char *path, char *const argv[] );     int  execvp  ( const char *file, char *const argv[] );     int  execve  ( const char *filename, char *const argv[],               char *const envp[] );     unsigned int  alarm  ( unsigned int secs );     void  exit  ( int status );     int  sigaction  ( int signum,                 const struct sigaction *act,                 struct sigaction *oldact );