Linux：more less tail head cat

more：
[quote]Usage: more [options] file...

Options:
-d display help instead of ring bell
-f count logical, rather than screen lines
-l suppress pause after form feed
-p suppress scroll, clean screen and disblay text
-c suppress scroll, display text and clean line ends
-u suppress underlining
-s squeeze multiple blank lines into one
-NUM specify the number of lines per screenful
+NUM display file beginning from line number NUM
+/STRING display file beginning from search string match
-V output version information and exit
[/quote]
less
比more灵活些，可以trl+f,ctrl+b

head
[quote]Usage: head [OPTION]... [FILE]...
Print the first 10 lines of each FILE to standard output.
With more than one FILE, precede each with a header giving the file name.
With no FILE, or when FILE is -, read standard input. [/quote]

tail
[quote]Usage: tail [OPTION]... [FILE]...
Print the last 10 lines of each FILE to standard output.
With more than one FILE, precede each with a header giving the file name.
With no FILE, or when FILE is -, read standard input.[/quote]

cat
[quote]Usage: cat [OPTION]... [FILE]...
Concatenate FILE(s), or standard input, to standard output.

-A, --show-all equivalent to -vET
-b, --number-nonblank number nonempty output lines, overrides -n
-e equivalent to -vE
-E, --show-ends display $ at end of each line
-n, --number number all output lines
-s, --squeeze-blank suppress repeated empty output lines
-t equivalent to -vT
-T, --show-tabs display TAB characters as ^I
-u (ignored)
-v, --show-nonprinting use ^ and M- notation, except for LFD and TAB
--help display this help and exit
--version output version information and exit

With no FILE, or when FILE is -, read standard input.

Examples:
cat f - g Output f's contents, then standard input, then g's contents.
cat Copy standard input to standard output [/quote]

某次面试，某个面试官问，这五个有什么区别？