GNU Info has commands to search through the indices of an Info file, which helps you find areas within an Info file which discuss a particular topic.
Look up a string in the indices for this Info file, and select a node to which the found index entry points.
Look up a string in the indices for this Info file, and show all the matches in a new virtual node, synthesized on the fly.
Move to the node containing the next matching index item from the last ‘i’ command.
Grovel the indices of all the known Info files on your system for a string, and build a menu of the possible matches.
The most efficient means of finding something quickly in a manual is
the ‘i’ command (
index-search). This command prompts for
a string, and then looks for that string in all the indices of the
current Info manual. If it finds a matching index entry, it displays
the node to which that entry refers and prints the full text of the
entry in the echo area. You can press ‘,’
next-index-match) to find more matches. A good Info manual
has all of its important concepts indexed, so the ‘i’ command
lets you use a manual as a reference.
If you don’t know what manual documents something, try the M-x index-apropos command. It prompts for a string and then looks up that string in all the indices of all the Info documents installed on your system. It can also be invoked from the command line; see --apropos.