Create a set of pipe file handlers
Assign stream for in and output to a program
Execute process (using argument list, environment)
Execute process (using argument list, environment)
Execute process (using argument list, environment; search path)
Execute a program in the path, and pass it an environment
Execute process
Execute process, search path
Execute process, search path using environment
Lock a file (advisory lock)
Retrieve file system information.
Flush cached data to disk
Return kernel time of day in GMT
Retrieve file system information.
Execute and feed command to system shell
Search for file in search path.
Return current domain name
Return host name
Return local timezone information
Return name of timezone information file
Pipe file to standard input/output of program
Read the timezone file and initialize time routines
Re-Read the local time files.
Seek to position in directory
Return current location in a directory
Wait for process to terminate.
Check whether the process is currently stopped.
Construct an exit status based on an return code and signal.
Construct an exit status based on a signal.