|
|
Simple to you not simple to me pattern matchin help
07-22-2007
Simple to you not simple to me pattern matchin help
|
|
Mined is a simple screen editor. At any instant, a window of 24 lines is visible on the screen. The current position in the file is shown by the cursor. Ordinary characters typed in are insert- ed at the cursor. Control characters and keys on the numeric keypad (at the right-hand side of the keyboard) are used to move the cursor and perform other functions. Commands exist to move forward and backward a word, and delete words either in front of the cursor or behind it. A word in this context is a sequence of characters delimited on both ends by white space (space, tab, line feed, start of file, or end of file). The commands for deleting characters and words also work on line feeds, making it possible to join two consecutive lines by deleting the line feed between them. The editor maintains one save buffer (not dis- played). Commands are present to move text from the file to the buffer, from the buffer to the file, and to write the buffer onto a new file. If the edited text cannot be written out due to a full disk, it may still be possible to copy the whole text to the save buffer and then write it to a different file on a different disk with CTRL-Q. It may also be possible to escape from the ed- itor with CTRL-S and remove some files. Some of the commands prompt for arguments (file names, search patterns, etc.). All commands that might result in loss of the file being edited prompt to ask for confirmation. A key (command or ordinary char- acter) can be repeated times by typing where is the escape key. Forward and backward searching requires a regular expression as the search pattern. Regular expressions follow the same rules as in the editor, These rules can be stated as: Any displayable character matches itself. . (period) matches any character ex- cept line feed. ^ (circumflex) matches the start of the line. $ (dollar sign) matches the end of the line. c matches the char- acter c (including period, circumflex, etc). [string] matches any of the characters in the string. [^string] matches any of the characters except those in the string. [x-y] matches any characters between x and y (e.g., [a-z]). Pattern* matches any number of occurrences of pattern. Some examples of regular ex- pressions are: The boy matches the string The boy ^$ matches any empty line. ^.$ matches any line containing exactly 1 character ^A.*.$ matches any line starting with an A, ending with a period. ^[A-Z]*$ matches any line containing only capital letters (or empty). [A-Z0-9] matches any line containing either a capital letter or a digit. .*X$ matches any line ending in X A.*B matches any line containing an A and then a B Control characters cannot be entered into a file simply by typing them because all of them are editor commands. To enter a control character, depress the ALT key, and then while holding it down, hit the ESC key. Release both ALT and ESC and type the control character. Control characters are displayed in reverse video. The commands are as follows. CURSOR MOTION
arrows Move the cursor in the indicated direction CTRL-A Move cursor to start of current line CTRL-Z Move cursor to end of current line CTRL-^ Move cursor to top of screen CTRL-_ Move cursor to end of screen CTRL-F Move cursor forward to start of next word CTRL-B Move cursor backward to start of previous word SCREEN MOTION
Home key Move to first character of the file End key Move to last character of the file PgUp key Scroll window up 23 lines (closer to start of the file) PgDn key Scroll window down 23 lines (closer to end of the file) CTRL-U Scroll window up 1 line CTRL-D Scroll window down 1 line MODIFYING TEXT
Del key Delete the character under the cursor Backspace Delete the character to left of the cursor CTRL-N Delete the next word CTRL-P Delete the previous word CTRL-T Delete tail of line (all characters from cursor to end of line) CTRL-O Open up the line (insert line feed and back up) CTRL-G Get and insert a file at the cursor position BUFFER OPERATIONS
CTRL-@ Set mark at current position for use with CTRL-C and CTRL-K CTRL-C Copy the text between the mark and the cursor into the buffer CTRL-K Delete text between mark and cursor; also copy it to the buffer CTRL-Y Yank contents of the buffer out and insert it at the cursor CTRL-Q Write the contents of the buffer onto a file MISCELLANEOUS
numeric + Search forward (prompts for regular expression) numeric - Search backward (prompts for regular expression) numeric 5 Display the file status CTRL-] Go to specific line CTRL-R Global replace pattern with string (from cursor to end) CTRL-L Line replace pattern with string CTRL-W Write the edited file back to the disk CTRL-X Exit the editor CTRL-S Fork off a shell (use CTRL-D to get back to the edi- tor) CTRL- Abort whatever the editor was doing and wait for com- mand CTRL-E Erase screen and redraw it CTRL-V Visit (edit) a new file Mined was designed by Andy Tanenbaum and written by Michiel Huis- jes.