+#f2# Find history events by search pattern and list them by date.
+whatwhen() {
+# {{{
+ local usage help ident format_l format_s first_char remain first last
+ usage='USAGE: whatwhen [options] <searchstring> <search range>'
+ help='Use' \`'whatwhen -h'\'' for further explanations.'
+ ident=${(l,${#${:-Usage: }},, ,)}
+ format_l="${ident}%s\t\t\t%s\n"
+ format_s="${format_l//(\\t)##/\\t}"
+ # Make the first char of the word to search for case
+ # insensitive; e.g. [aA]
+ first_char=[${(L)1[1]}${(U)1[1]}]
+ remain=${1[2,-1]}
+ # Default search range is `-100'.
+ first=${2:-\-100}
+ # Optional, just used for `<first> <last>' given.
+ last=$3
+ case $1 in
+ ("")
+ printf '%s\n\n' 'ERROR: No search string specified. Aborting.'
+ printf '%s\n%s\n\n' ${usage} ${help} && return 1
+ ;;
+ (-h)
+ printf '%s\n\n' ${usage}
+ print 'OPTIONS:'
+ printf $format_l '-h' 'show help text'
+ print '\f'
+ print 'SEARCH RANGE:'
+ printf $format_l "'0'" 'the whole history,'
+ printf $format_l '-<n>' 'offset to the current history number; (default: -100)'
+ printf $format_s '<[-]first> [<last>]' 'just searching within a give range'
+ printf '\n%s\n' 'EXAMPLES:'
+ printf ${format_l/(\\t)/} 'whatwhen grml' '# Range is set to -100 by default.'
+ printf $format_l 'whatwhen zsh -250'
+ printf $format_l 'whatwhen foo 1 99'
+ ;;
+ (\?)
+ printf '%s\n%s\n\n' ${usage} ${help} && return 1
+ ;;
+ (*)
+ # -l list results on stout rather than invoking $EDITOR.
+ # -i Print dates as in YYYY-MM-DD.
+ # -m Search for a - quoted - pattern within the history.
+ fc -li -m "*${first_char}${remain}*" $first $last
+ ;;
+ esac
+# }}}
+}
+