CS469/569 - Linux and Unix Administration and Networking Spring 2022

Displaying ./code/02-15/README

h5 - questions?
q4 - check canvas for grades/solutions.
q5 - released by Thursday's class, due by Friday.  Topic - bash (still/again)
h6 - released by Thursday's class, due Monday.  Topic - bash (still/again)

take attendance

shell pattern versus regular expression
shell patterns: ? - any character
                * - match any string
	        {} - some number of repetitions
		[] - character group
reg exp: * - 0 or more repetitions of the thing before it
         | - or
	 () - grouping
           - concatenation  (hello)*(bye)*
         []
	 ? - 0 or 1 of the preceding thing (hello)?
	 {} - referring back to a match in ().
	 other differences
	 grep
	 
New today - additional scripting utilities and programs

Example data files
- /u1/junk/kinne/weather
- /u1/junk/kinne/river
- /u1/junk/kinne/GSE8*
- /etc/passwd
- last output
- /proc

builtin versus command

builtin: not a program, the shell itself recognizes the name and runs some function in the shell code.  e.g., ulimit, alias

command: a program that runs (and is normally in a directory in PATH, use which to see where the program actually is)