Difference between revisions of "Regexp Search"

Revision as of 01:05, 22 February 2016

[C-M-s] (or M-x isearch-forward-regexp) : incremental forward search matching regexp
[C-M-r] (or M-x isearch-backward-regexp) : incremental backward search matching regexp

alternative

invoke incremental search by either C-s (isearch-forward) or C-r (isearch-backward)
note the I-search: prompt in the echo area
type M-r
note the Pending regexp I-search: prompt in the echo area

@@ Line 1: / Line 1: @@
-== Syntax ==
+# {{CommandKeys|C-M-s|isearch-forward-regexp}} : incremental forward search matching regexp
+# {{CommandKeys|C-M-r|isearch-backward-regexp}} :   incremental backward search matching regexp
-The following characters are special : . * + ? ^ $ \ [
+=== alternative ===
-Between brackets [], the following are special : ] - ^
+# invoke incremental search by either '''C-s''' (isearch-forward) or '''C-r''' (isearch-backward)
+# note the ''I-search:'' prompt in the echo area
+# type '''M-r'''
+# note the ''Pending regexp I-search:'' prompt in the echo area
-Many characters are special when they follow a backslash – see below.
+[[Category:Search]]
-  .        any character (but newline)
-  *        previous character or group, repeated 0 or more time
-  +        previous character or group, repeated 1 or more time
-  ?        previous character or group, repeated 0 or 1 time
-  ^        start of line
-  $        end of line
-  [...]    any character between brackets
-  [^..]    any character not in the brackets
-  [a-z]    any character between a and z
-  \        prevents interpretation of following special char
-  \|       or
-  \w       word constituent
-  \b       word boundary
-  \sc      character with c syntax (e.g. \s- for whitespace char)
-  \( \)    start\end of group
-  \< \>    start\end of word
-  \` \'    start\end of buffer
-  \1       string matched by the first group
-  \n       string matched by the nth group
-  \{3\}    previous character or group, repeated 3 times
-  \{3,\}   previous character or group, repeated 3 or more times
-  \{3,6\}  previous character or group, repeated 3 to 6 times
-.?, +?, and ?? are non-greedy versions of ., +, and ?
-\W, \B, and \Sc match any character that does not match \w, \b, and \sc
-Characters are organized by category. Use C-u C-x = to display the category of the character under the cursor.
-  \ca      ascii character
-  \Ca      non-ascii character (newline included)
-  \cl      latin character
-  \cg      greek character
-Here are some [[syntax_classes?]] that can be used between brackets, [].
-  [:digit:]  a digit, same as [0-9]
-  [:upper:]  a letter in uppercase
-  [:space:]  a whitespace character, as defined by the syntax table
-  [:xdigit:] an hexadecimal digit
-  [:cntrl:]  a control character
-  [:ascii:]  an ascii character
-Syntax classes:
-  \s-   whitespace character        \s/   character quote character
-  \sw   word constituent            \s$   paired delimiter
-  \s_   symbol constituent          \s'   expression prefix
-  \s.   punctuation character       \s<   comment starter
-  \s(   open delimiter character    \s>   comment ender
-  \s)   close delimiter character   \s!   generic comment delimiter
-  \s"   string quote character      \s|   generic string delimiter
-  \s\   escape character
-== Regexp Examples ==
- [-+[:digit:]]                     digit or + or - sign
- \(\+\|-\)?[0-9]+\(\.[0-9]+\)?     decimal number (-2 or 1.5 but not .2 or 1.)
- \(\w+\) +\1\>                     two consecutive, identical words
- \<[[:upper:]]\w*                  word starting with an uppercase letter
-  +$                               trailing whitespaces (note the starting SPC)
- \w\{20,\}                         word with 20 letters or more
- \w+phony\>                        word ending by phony
- \(19\|20\)[0-9]\{2\}              year 1900-2099
- ^.\{6,\}                          at least 6 symbols
- ^[a-zA-Z0-9_]\{3,16\}$            decent string for a user name
- <tag[^> C-q C-j ]*>\(.*?\)</tag>  html tag
-== Emacs Commands that Use Regular Expressions ==
- C-M-s                   incremental forward search matching regexp
- C-M-r                   incremental backward search matching regexp
- replace-regexp          replace string matching regexp
- query-replace-regexp    same, but query before each replacement
- align-regexp            align, using strings matching regexp as delimiters
- highlight-regexp        highlight strings matching regexp
- occur                   show lines containing a match
- multi-occur             show lines in all buffers containing a match
- how-many                count the number of strings matching regexp
- keep-lines              delete all lines except those containing matches
- flush-lines             delete lines containing matches
- grep                    call unix grep command and put result in a buffer
- lgrep                   user-friendly interface to the grep command
- rgrep                   recursive grep
- dired-do-copy-regexp    copy files with names matching regexp
- dired-do-rename-regexp  rename files matching regexp
- find-grep-dired         display files containing matches for regexp with Dired
-== See Also ==
-[[Re-builder]] build regexp interactively in buffer

Difference between revisions of "Regexp Search"

Revision as of 01:05, 22 February 2016

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