The commands in this section visit and search all the files listed in the selected tags table, one by one. For these commands, the tags table serves only to specify a sequence of files to search. These commands scan the list of tags tables starting with the first tags table (if any) that describes the current file, proceed from there to the end of the list, and then scan from the beginning of the list until they have covered all the tables in the list.
query-replace-regexpon each file in the selected tags table.
M-x tags-search reads a regexp using the minibuffer, then
searches for matches in all the files in the selected tags table, one
file at a time. It displays the name of the file being searched so you
can follow its progress. As soon as it finds an occurrence,
Having found one match, you probably want to find all the rest. To find
one more match, type M-, (
tags-loop-continue) to resume the
tags-search. This searches the rest of the current buffer, followed
by the remaining files of the tags table.
M-x tags-query-replace performs a single
query-replace-regexp through all the files in the tags table. It
reads a regexp to search for and a string to replace with, just like
ordinary M-x query-replace-regexp. It searches much like M-x
tags-search, but repeatedly, processing matches according to your
input. See Replace, for more information on query replace.
You can control the case-sensitivity of tags search commands by
customizing the value of the variable
default is to use the same setting as the value of
case-fold-search (see Search Case).
It is possible to get through all the files in the tags table with a single invocation of M-x tags-query-replace. But often it is useful to exit temporarily, which you can do with any input event that has no special query replace meaning. You can resume the query replace subsequently by typing M-,; this command resumes the last tags search or replace command that you did. For instance, to skip the rest of the current file, you can type M-> M-,.
The commands in this section carry out much broader searches than the
find-tag family. The
find-tag commands search only for
definitions of tags that match your substring or regexp. The commands
tags-query-replace find every occurrence
of the regexp, as ordinary search commands and replace commands do in
the current buffer.
These commands create buffers only temporarily for the files that they have to search (those which are not already visited in Emacs buffers). Buffers in which no match is found are quickly killed; the others continue to exist.
It may have struck you that
tags-search is a lot like
grep. You can also run
grep itself as an inferior of
Emacs and have Emacs show you the matching lines one by one.
See Grep Searching.