shell more less cat

cat        连续显示、查看文件内容more        分页查看文件内容less 分页可控制查看文件内容通俗点说：cat一次性把文件内容全部显示出来，管你看不看得清，显示完了cat命令就返回了，不能进行交互式操作，适合察看内容短小、不超过一屏的文件；more比cat强大一点，支持分页显示，你可以ctrl+B ctrl+F .....上下滚屏，但是不支持像shift+G（跳到文件尾）这种操作；less比more更强大一点，支持各种命令，随便翻页、跳转、查找.....想怎么看，就怎么看，爱怎么看，就怎么看。                   SUMMARY OF LESS COMMANDS       Commands marked with * may be preceded by a number, N.       Notes in parentheses indicate the behavior if N is given.   h  H                 Display this help.   q  :q  Q  :Q  ZZ     Exit. ---------------------------------------------------------------------------                            MOVING   e  ^E  j  ^N  CR  *  Forward  one line   (or N lines).   y  ^Y  k  ^K  ^P  *  Backward one line   (or N lines).   f  ^F  ^V  SPACE  *  Forward  one window (or N lines).   b  ^B  ESC-v      *  Backward one window (or N lines).   z                 *  Forward  one window (and set window to N).   w                 *  Backward one window (and set window to N).   ESC-SPACE         *  Forward  one window, but don't stop at end-of-file.   d  ^D             *  Forward  one half-window (and set half-window to N).   u  ^U             *  Backward one half-window (and set half-window to N).   ESC-)  RightArrow *  Left  one half screen width (or N positions).   ESC-(  LeftArrow  *  Right one half screen width (or N positions).   F                    Forward forever; like "tail -f".   r  ^R  ^L            Repaint screen.   R                    Repaint screen, discarding buffered input.         ---------------------------------------------------         Default "window" is the screen height.         Default "half-window" is half of the screen height. ---------------------------------------------------------------------------                           SEARCHING   /pattern          *  Search forward for (N-th) matching line.   ?pattern          *  Search backward for (N-th) matching line.   n                 *  Repeat previous search (for N-th occurrence).   N                 *  Repeat previous search in reverse direction.   ESC-n             *  Repeat previous search, spanning files.   ESC-N             *  Repeat previous search, reverse dir. & spanning files.   ESC-u                Undo (toggle) search highlighting.         ---------------------------------------------------         Search patterns may be modified by one or more of:         ^N or !  Search for NON-matching lines.         ^E or *  Search multiple files (pass thru END OF FILE).         ^F or @  Start search at FIRST file (for /) or last file (for ?).         ^K       Highlight matches, but don't move (KEEP position).         ^R       Don't use REGULAR EXPRESSIONS. ---------------------------------------------------------------------------                            JUMPING   g  <  ESC-<       *  Go to first line in file (or line N).   G  >  ESC->       *  Go to last line in file (or line N).   p  %              *  Go to beginning of file (or N percent into file).   t                 *  Go to the (N-th) next tag.   T                 *  Go to the (N-th) previous tag.   {  (  [           *  Find close bracket } ) ].   }  )  ]           *  Find open bracket { ( [.   ESC-^F <c1> <c2>  *  Find close bracket <c2>.   ESC-^B <c1> <c2>  *  Find open bracket <c1>         ---------------------------------------------------         Each "find close bracket" command goes forward to the close bracket           matching the (N-th) open bracket in the top line.         Each "find open bracket" command goes backward to the open bracket           matching the (N-th) close bracket in the bottom line.   m<letter>            Mark the current position with <letter>.   '<letter>            Go to a previously marked position.   ''                   Go to the previous position.   ^X^X                 Same as '.         ---------------------------------------------------         A mark is any upper-case or lower-case letter.         Certain marks are predefined:              ^  means  beginning of the file              $  means  end of the file ---------------------------------------------------------------------------                         CHANGING FILES   :e [file]            Examine a new file.   ^X^V                 Same as :e.   :n                *  Examine the (N-th) next file from the command line.   :p                *  Examine the (N-th) previous file from the command line.   :x                *  Examine the first (or N-th) file from the command line.   :d                   Delete the current file from the command line list.   =  ^G  :f            Print current file name. ---------------------------------------------------------------------------                     MISCELLANEOUS COMMANDS   -<flag>              Toggle a command line option [see OPTIONS below].   --<name>             Toggle a command line option, by name.   _<flag>              Display the setting of a command line option.   __<name>             Display the setting of an option, by name.   +cmd                 Execute the less cmd each time a new file is examined.   !command             Execute the shell command with $SHELL.   |Xcommand            Pipe file between current pos & mark X to shell command.   v                    Edit the current file with $VISUAL or $EDITOR.   V                    Print version number of "less". ---------------------------------------------------------------------------                            OPTIONS         Most options may be changed either on the command line,         or from within less by using the - or -- command.         Options may be given in one of two forms: either a single         character preceded by a -, or a name preceeded by --.   -?  ........  --help                   Display help (from command line).   -a  ........  --search-skip-screen                   Forward search skips current screen.   -b [N]  ....  --buffers=[N]                   Number of buffers.   -B  ........  --auto-buffers                   Don't automatically allocate buffers for pipes.   -c  -C  ....  --clear-screen  --CLEAR-SCREEN                   Repaint by scrolling/clearing.   -d  ........  --dumb                   Dumb terminal.   -D [xn.n]  .  --color=xn.n                   Set screen colors. (MS-DOS only)   -e  -E  ....  --quit-at-eof  --QUIT-AT-EOF                   Quit at end of file.   -f  ........  --force                   Force open non-regular files.   -F  ........  --quit-if-one-screen                   Quit if entire file fits on first screen.   -g  ........  --hilite-search                   Highlight only last match for searches.   -G  ........  --HILITE-SEARCH                   Don't highlight any matches for searches.   -h [N]  ....  --max-back-scroll=[N]                   Backward scroll limit.   -i  ........  --ignore-case                   Ignore case in searches that do not contain uppercase.   -I  ........  --IGNORE-CASE                   Ignore case in all searches.   -j [N]  ....  --jump-target=[N]                   Screen position of target lines.   -J  ........  --status-column                   Display a status column at left edge of screen.   -k [file]  .  --lesskey-file=[file]                   Use a lesskey file.   -L  ........  --no-lessopen                   Ignore the LESSOPEN environment variable.   -m  -M  ....  --long-prompt  --LONG-PROMPT                   Set prompt style.   -n  -N  ....  --line-numbers  --LINE-NUMBERS                   Use line numbers.   -o [file]  .  --log-file=[file]                   Copy to log file (standard input only).   -O [file]  .  --LOG-FILE=[file]                   Copy to log file (unconditionally overwrite).   -p [pattern]  --pattern=[pattern]                   Start at pattern (from command line).   -P [prompt]   --prompt=[prompt]                   Define new prompt.   -q  -Q  ....  --quiet  --QUIET  --silent --SILENT                   Quiet the terminal bell.   -r  -R  ....  --raw-control-chars  --RAW-CONTROL-CHARS                   Output "raw" control characters.   -s  ........  --squeeze-blank-lines                   Squeeze multiple blank lines.   -S  ........  --chop-long-lines                   Chop long lines.   -t [tag]  ..  --tag=[tag]                   Find a tag.   -T [tagsfile] --tag-file=[tagsfile]                   Use an alternate tags file.   -u  -U  ....  --underline-special  --UNDERLINE-SPECIAL                   Change handling of backspaces.   -V  ........  --version                   Display the version number of "less".   -w  ........  --hilite-unread                   Highlight first new line after forward-screen.   -W  ........  --HILITE-UNREAD                   Highlight first new line after any forward movement.   -x [N[,...]]  --tabs=[N[,...]]                   Set tab stops.   -X  ........  --no-init                   Don't use termcap init/deinit strings.                 --no-keypad                   Don't use termcap keypad init/deinit strings.   -y [N]  ....  --max-forw-scroll=[N]                   Forward scroll limit.   -z [N]  ....  --window=[N]                   Set size of window.   -" [c[c]]  .  --quotes=[c[c]]                   Set shell quote characters.   -~  ........  --tilde                   Don't display tildes after end of file.   -# [N]  ....  --shift=[N]                   Horizontal scroll amount (0 = one half screen width) ---------------------------------------------------------------------------                           LINE EDITING         These keys can be used to edit text being entered         on the "command line" at the bottom of the screen. RightArrow                       ESC-l     Move cursor right one character. LeftArrow                        ESC-h     Move cursor left one character. CNTL-RightArrow  ESC-RightArrow  ESC-w     Move cursor right one word. CNTL-LeftArrow   ESC-LeftArrow   ESC-b     Move cursor left one word. HOME                             ESC-0     Move cursor to start of line. END                              ESC-$     Move cursor to end of line. BACKSPACE                                  Delete char to left of cursor. DELETE                           ESC-x     Delete char under cursor. CNTL-BACKSPACE   ESC-BACKSPACE             Delete word to left of cursor. CNTL-DELETE      ESC-DELETE      ESC-X     Delete word under cursor. CNTL-U           ESC (MS-DOS only)         Delete entire line. UpArrow                          ESC-k     Retrieve previous command line. DownArrow                        ESC-j     Retrieve next command line. TAB                                        Complete filename & cycle. SHIFT-TAB                        ESC-TAB   Complete filename & reverse cycle. CNTL-L                                     Complete filename, list all. HELP -- END -- Press g to see it again, or q when done