FIGNORE
A colon-separated list of suffixes to ignore when performing filename comple- tion. A filename whose suffix matches one of the entries in FIGNORE is excluded from the list of matched filenames. A sample value is ‘.o:~’
FUNCNAME
An array variable containing the names of all shell functions currently in the execution call stack. The element with index 0 is the name of any currently- executing shell function. The bottom-most element (the one with the highest index) is "main". This variable exists only when a shell function is executing.
Assignments to FUNCNAME have no effect and return an error status. If FUNCNAME is unset, it loses its special properties, even if it is subsequently reset.
This variable can be used with BASH_LINENO and BASH_SOURCE. Each element of FUNCNAME has corresponding elements in BASH_LINENO and BASH_SOURCE to describe the call stack. For instance, ${FUNCNAME[$i]} was called from the file ${BASH_SOURCE[$i+1]} at line number ${BASH_LINENO[$i]}. The caller builtin displays the current call stack using this information.
FUNCNEST
If set to a numeric value greater than 0, defines a maximum function nesting level. Function invocations that exceed this nesting level will cause the current command to abort.
GLOBIGNORE
A colon-separated list of patterns defining the set of filenames to be ignored by filename expansion. If a filename matched by a filename expansion pattern also matches one of the patterns in GLOBIGNORE, it is removed from the list of matches.
GROUPS
An array variable containing the list of groups of which the current user is a member. Assignments to GROUPS have no effect and return an error status. If
GROUPS is unset, it loses its special properties, even if it is subsequently reset. histchars
Up to three characters which control history expansion, quick substitution, and tokenization (see Section 9.3 [History Interaction], page 135). The first charac- ter is the history expansion character, that is, the character which signifies the start of a history expansion, normally ‘!’. The second character is the character which signifies ‘quick substitution’ when seen as the first character on a line, normally ‘^’. The optional third character is the character which indicates that the remainder of the line is a comment when found as the first character of a word, usually ‘#’. The history comment character causes history substitution to be skipped for the remaining words on the line. It does not necessarily cause the shell parser to treat the rest of the line as a comment.
HISTCMD
The history number, or index in the history list, of the current command. If
HISTCMD is unset, it loses its special properties, even if it is subsequently reset.
HISTCONTROL
A colon-separated list of values controlling how commands are saved on the history list. If the list of values includes ‘ignorespace’, lines which begin with a space character are not saved in the history list. A value of ‘ignoredups’ causes lines which match the previous history entry to not be saved. A value of ‘ignoreboth’ is shorthand for ‘ignorespace’ and ‘ignoredups’. A value of