These command-line editor keys can be used to complete filenames, commands and variables.
Lists commands and pathnames that match the current word.
Command, pathname and variable completion. If the cursor is positioned on the first word of the command-line, command pathname is performed, else pathname or variable completion is performed. The word is expanded to the closest matching command, pathname or variable. Characters are appended up to the point that they would cause more than one. If a complete pathname results for pathname completion, gsh appends a "/" if the pathname is a directory; otherwise, it appends a space.
Note that if there is more than one match for the partial command, gsh will sound a beep on the speaker. You can use the CTRL-D (list-choices) command to see the list of possible matches, and should either finish entering the command manually or type enough additional characters to guarantee a unique match.
If the FIGNORE environment variable is set, gsh ignores filenames (when doing completion) that end with any of the suffixes in $FIGNORE. See the Section called Description of Predefined Shell Variables in the Chapter called Shell Variables for more information regarding the FIGNORE environment variable.