Search commands move though the buffer, in either the forward or the reverse direction, looking for text that matches a search pattern. Search commands prompt for the search pattern in the echo line. The search pattern used by the last search command is remembered, and displayed in the prompt. If you want to use this pattern again, just hit carriage return at the prompt.

In search strings, all characters stand for themselves, and all searches are normally case insensitive. The case insensitivity may be defeated with the "fold-case" command, described below. The newline characters at the ends of the lines are considered to have hexadecimal value 0A, and can be matched by a linefeed (Control-J) in the search string.

A carriage return can be searched for by preceding it with Control-Q in the search string. On PC-DOS, CP/M and FlexOS this will not match the carriage return in the CR-LF character pair that normally terminates a line of text. It will only match a bare carriage return that has no following line feed.

MicroEMACS supports regular expression searches using a subset of POSIX regular expressions:

• . (dot) matches any character

• character classes (square brackets with optional ^ negation operator)

• groups (parentheses)

• alternatives (|)

• ^ (start of line) and $ (end of line)

• ? (zero or one occurrence)

• * (zero or more occurrences)

• + (one or more occurrences)

If you configure MicroEMACS with the --with-pcre2 option, MicroEMACS will use the PCRE2 library to support Perl-compatible regular expressions. See Building a MicroEMACS.

C-S, M-S (forw-search)

Search forward, from the current location, toward the end of the buffer. If found, dot is positioned after the matched text. If the text is not found, dot does not move.

The C-S form of the command is not usable if the terminal being used required XON/XOFF support. In fact, if you use this format of the command on such a terminal, it will hang until you type C-Q.

The M-S form of this command is easily entered on the Z-29 keyboard by pressing the F1 key.

C-R (back-search)

Search reverse, from the current location, toward the front of the buffer. If found, dot is positioned at the first character of the matched text. If the text is not found, dot does not move.

M-C-S (forw-regexp-search)

Similar to forw-search, except that the search string is a regular expression, and searches cannot cross line boundaries.

M-C-R (back-regexp-search)

Similar to back-search, except that the search string is a regular expression, and searches cannot cross line boundaries.

M-C-F (fold-case)

Enable or disable case folding in searches, depending on the argument to the command. If the argument is zero, case folding is disabled, and searches will be sensitive to case. If the argument is non-zero, case folding is enabled, and searches will NOT be sensitive to case.

M-P (search-paren)

Search for a match of the character at the dot. If the character is a parenthesis or bracketing character, move the dot to the matching parenthesis or bracket, taking into account nesting and C-style comments. A parenthesis or bracketing character is one of the following: (){}[]<>

Pad-1,Shift-5 (search-again)

Repeat the last forw-search command (C-S, M-S) or prev-search command (C-R, M-R), without prompting for a string. This command is bound to two keys on the numeric keypad of the Z-29 terminal: the 1 key, and the shifted 5 key. On PCs, this function is also bound to F9.

C-X S (forw-i-search)

Enters incremental search mode, with the initial search direction being forward. In incremental search mode the following keys are recognized.

• C-N finds the next occurence of the string (if it is first thing typed, reuse the previous string).

• C-P finds the previous occurence of the string (if it is the first thing typed, reuse the previous string).

• C-S (or C-F) switches the search direction to forward, and finds the next occurrence of the string.

• C-R (or C-B) switches the search direction to reverse, and finds the next occurrence of the string.

• C-Q (or C-^) quotes the next character (allows searching for C-N, etc.).

• ESC exits from incremental search mode.

• C-G restores dot to original location before incremental search mode was entered, then exits from incremental search mode.

• DEL undoes the effect of the last character typed in the search string.

• C-U, C-X, C-J, and all non-Control characters accumulate into search string.

• All other control characters exit from incremental search mode and are interpreted as normal commands.

C-X R (back-i-search)

Enters incremental search mode, with the initial search direction being reverse. Otherwise identical to C-X S.

M-Q,M-% (query-replace)

Search and replace with query. This command prompts for a search string and a replace string, then searches forward for the search string. After each occurrence of the search string is found, the dot is placed after the string, and the user is prompted for action. Enter one of the following characters:

• space or , (comma) causes the string to be replaced, and the next occurrence is searched.

• . (period) causes the string to replaced, and quits the search.

• n causes the string to be skipped without being replaced, and the next occurrence is searched.

• ! causes all subsequent occurrences of the string to be replaced without prompting.

• Control-G quits the search without any further replacements.

Normally this command adjusts the capitalization of the new string to match the old string when it performs a replacement. You can defeat this "feature" if you prefix this command with an argument (the argument value is ignored).

M-R (replace-string)

Prompt for a search string and a replacement string, then search forward for all occurrences of the search string, replacing each one with the replacement string. Do not prompt the user for confirmation at each replacement, as in the query-replace command.

Normally this command adjusts the capitalization of the new string to match the old string when it performs a replacement. You can defeat this "feature" if you prefix this command with an argument (the argument value is ignored).

M-? (reg-query-replace)

Similar to query-replace, except that the search string is a regular expression. If MicroEMACS was built with PCRE2 suport, the replacement string can contain the following special sequences:

• $$: insert a dollar character

• $n or ${n}: insert the contents of group n

• $0 or $&: insert the entire matched substring

• $`: insert the substring that precedes the match

• $': insert the substring that follows the match

• $_: insert the entire input string

• $*MARK or ${*MARK} insert a control verb name

See the PCRE2 documentation for substitions for details.

If MicroEMACS was not built with PCRE2 support, the replacement string can contain the following special sequences:

• & stands for the entire matched string.

• \n, where n is a digit in the range 0-9, stands for the nth matched group (where groups are delineated by parentheses in the regular expression pattern).

• \ followed by either \ or & stands for that character itself, without the leading \.

M-/ (reg-replace)

Similar to reg-query-replace, except that the user is not prompted to confirm each replacement, as in replace-string.

C-X I (spell-region)

This command uses ispell to spell-check the current region (the text between the mark and the dot). At each misspelled word, MicroEMACS prompts for an action:

• q or C-G aborts the spell checking.

• Space ignores the misspelled word

• a ignores the misspelled word and adds it to ispell's list of words to ignore in the future.

• 0 to 9 replaces the misspelled word with one of up to ten suggestions; the suggestions are shown in the prompt on the echo line.

• r prompts for a string to replace the word.

M-$ (spell-word)

Similar to spell-region, except that it checks only the word under the cursor.