# HG changeset patch
# User Frank Terbeck <ft@grml.org>
# Date 1196887836 -3600
# Node ID 6125ddcf0131b5aa71ab99f2fe9ee0d63247f559
# Parent  3e70aced743451fc640bdf92e1db867fdc5a0682
Introducing check_com() to check for the existence of commands

This makes use of features, that require zsh v3.1.7+.

usage: check_com [-c] <command>

If -c is given, check_com() only checks for commands. Else it checks
for the given word in reserved words, commands, aliases, builtins and
functions. If used correctly, check_com() does not output anything,
so no '>/dev/null 2>&1' stuff is needed.

diff -r 3e70aced7434 -r 6125ddcf0131 etc/skel/.zshrc
--- a/etc/skel/.zshrc	Tue Dec 04 19:06:09 2007 +0100
+++ b/etc/skel/.zshrc	Wed Dec 05 21:50:36 2007 +0100
@@ -23,17 +23,17 @@
 
 # autoloading stuff {{{
 # associate types and extensions (be aware with perl scripts and anwanted behaviour!)
-#  type zsh-mime-setup &>/dev/null || { autoload zsh-mime-setup && zsh-mime-setup }
+#  check_com zsh-mime-setup || { autoload zsh-mime-setup && zsh-mime-setup }
 #  alias -s pl='perl -S'
 # }}}
 
 # completion system {{{
 # just make sure it is loaded in this file too
-  type compinit &>/dev/null || { autoload -U compinit && compinit }
+  check_com compinit || { autoload -U compinit && compinit }
 # }}}
 
 # make sure isgrmlsmall is defined {{{
-  type isgrmlsmall &>/dev/null || function isgrmlsmall () { return 1 }
+  check_com isgrmlsmall || function isgrmlsmall () { return 1 }
 # }}}
 
 ## variables {{{
@@ -48,10 +48,10 @@
   if [[ -z "$BROWSER" ]] ; then
      if [[ -n "$DISPLAY" ]] ; then
         #v# If X11 is running
-        [[ -x $(type firefox) ]] && export BROWSER=firefox
+        check_com -c firefox && export BROWSER=firefox
      else
         #v# If no X11 is running
-        [[ -x $(type w3m) ]] && export BROWSER=w3m
+        check_com -c w3m && export BROWSER=w3m
      fi
   fi
   #v#
@@ -142,7 +142,7 @@
   alias conkeror='firefox -chrome chrome://conkeror/content'
 
 # arch/tla stuff
-  if type -p tla &>/dev/null ; then
+  if check_com -c tla ; then
      #a2# Execute \kbd{tla what-changed --diffs | less}
      alias tdi='tla what-changed --diffs | less'
      #a2# Execute \kbd{tla-buildpackage}
@@ -197,7 +197,7 @@
   #a2# Execute \kbd{mkdir -o}
   alias md='mkdir -p'
 
-  [[ -x $(type ipython) ]] && alias ips='ipython -p sh'
+  check_com -c ipython && alias ips='ipython -p sh'
 
 # console stuff
   #a2# Execute \kbd{mplayer -vo fbdev}
@@ -214,7 +214,7 @@
   alias insecscp='scp -o "StrictHostKeyChecking=no" -o "UserKnownHostsFile=/dev/null"'
 
 # Use 'g' instead of 'git':
-  type g &>/dev/null || alias g='git'
+  check_com g || alias g='git'
 
 # use colors when browsing man pages, but only if not using LESS_TERMCAP_* from /etc/zsh/zshenv:
   if [[ -z "$LESS_TERMCAP_md" ]] ; then
@@ -222,22 +222,22 @@
   fi
 
 # check whether Debian's package management (dpkg) is running
-  if type salias &>/dev/null ; then
+  if check_com salias ; then
     #a2# Check whether a dpkg instance is currently running
     salias check_dpkg_running="dpkg_running"
   fi
 
 # work around non utf8 capable software in utf environment via $LANG and luit
-  if type isutfenv &>/dev/null && type luit &>/dev/null; then
-     if [[ -x $(type mrxvt) ]] ; then
+  if check_com isutfenv && check_com luit ; then
+     if check_com -c mrxvt ; then
         isutfenv && [[ -n "$LANG" ]] && alias mrxvt="LANG=${LANG/(#b)(*)[.@]*/$match[1].iso885915} luit mrxvt"
      fi
 
-     if [[ -x $(type aterm) ]] ; then
+     if check_com -c aterm ; then
         isutfenv && [[ -n "$LANG" ]] && alias aterm="LANG=${LANG/(#b)(*)[.@]*/$match[1].iso885915} luit aterm"
      fi
 
-     if [[ -x $(type centericq) ]] ; then
+     if check_com -c centericq ; then
         isutfenv && [[ -n "$LANG" ]] && alias centericq="LANG=${LANG/(#b)(*)[.@]*/$match[1].iso885915} luit centericq"
      fi
   fi
@@ -278,7 +278,7 @@
   wodeb ()  { ${=BROWSER} "http://packages.debian.org/search?keywords=$1&searchon=contents&suite=${2:=unstable}&section=all" }
 
   #m# f4 gex() Exact search via Google
-  which google &>/dev/null && gex () { google "\"[ $1]\" $*" } # exact search at google
+  check_com google && gex () { google "\"[ $1]\" $*" } # exact search at google
 
 # misc
   #f5# Backup \kbd{file {\rm to} file\_timestamp}
@@ -337,7 +337,7 @@
   #f5# \kbd{cd} to /usr/share/doc/\textit{package}
   doc() { cd /usr/share/doc/$1 && ls }
   _doc() { _files -W /usr/share/doc -/ }
-  type compdef &>/dev/null && compdef _doc doc
+  check_com compdef && compdef _doc doc
 
 #f5# Make screenshot
   sshot() {
@@ -904,7 +904,7 @@
 
 # highlight important stuff in diff output, usage example: hg diff | hidiff
   #m# a2 hidiff \kbd{histring} oneliner for diffs
-  [[ -x $(type histring) ]] && \
+  check_com -c histring && \
   alias hidiff="histring -fE '^Comparing files .*|^diff .*' | histring -c yellow -fE '^\-.*' | histring -c green -fE '^\+.*'"
 
 # rename pictures based on information found in exif headers
@@ -973,7 +973,7 @@
 
 # hl() highlighted less
 # http://ft.bewatermyfriend.org/comp/data/zsh/zfunct.html
-  if [[ -x $(type highlight) ]] ; then
+  if check_com -c highlight ; then
     function hl() {
       local theme lang
       theme=${HL_THEME:-""}
@@ -1105,7 +1105,7 @@
 # }}}
 
 # mercurial related stuff {{{
-  if type -p hg &>/dev/null ; then
+  if check_com -c hg ; then
   # gnu like diff for mercurial
   # http://www.selenic.com/mercurial/wiki/index.cgi/TipsAndTricks
     #f5# GNU like diff for mercurial
@@ -1186,7 +1186,7 @@
 
 # Work around ion/xterm resize bug.
 #if [[ "$SHLVL" -eq 1 ]]; then
-#       if [[ -x $(type resize) ]]; then
+#       if check_com -c resize ; then
 #               eval `resize </dev/null`
 #       fi
 #fi
diff -r 3e70aced7434 -r 6125ddcf0131 etc/zsh/zshrc
--- a/etc/zsh/zshrc	Tue Dec 04 19:06:09 2007 +0100
+++ b/etc/zsh/zshrc	Wed Dec 05 21:50:36 2007 +0100
@@ -105,6 +105,42 @@
   [[ -r /etc/sysconfig/keyboard ]] && source /etc/sysconfig/keyboard
   [[ -r /etc/timezone ]] && TZ=$(cat /etc/timezone)
 # }}}
+
+# utility functions {{{
+  # this function checks if a command exists and returns either true
+  # or false. This avoids using 'which' and 'whence', which will
+  # avoid problems with aliases for which on certain weird systems. :-)
+  check_com() {
+    local -i comonly
+
+    if [[ ${1} == '-c' ]] ; then
+      (( comonly = 1 ))
+      shift
+    else
+      (( comonly = 0 ))
+    fi
+
+    if (( ${#argv} != 1 )) ; then
+      printf 'usage: check_com [-c] <command>\n' >&2
+      return 1
+    fi
+
+    if (( comonly > 0 )) ; then
+      [[ -n ${commands[$1]}  ]] && return 0
+      return 1
+    fi
+
+    if   [[ -n ${commands[$1]}  ]] \
+      || [[ -n ${functions[$1]} ]] \
+      || [[ -n ${aliases[$1]}   ]] \
+      || [[ -n ${reswords[$1]}  ]] ; then
+
+      return 0
+    fi
+
+    return 1
+  }
+#}}}
 
 # check for potentially old files in 'completion.d' {{{
   setopt extendedglob
@@ -231,7 +267,7 @@
 
 # {{{ set some variables
   #v#
-  if type -p vim &>/dev/null ; then
+  if check_com -c vim ; then
      export EDITOR=${EDITOR:-vim}
   else
      export EDITOR=${EDITOR:-vi}
@@ -244,7 +280,7 @@
   export SHELL='/bin/zsh'
 
   # color setup for ls:
-  [[ -x $(which dircolors) ]] && eval `dircolors -b`
+  check_com -c dircolors && eval `dircolors -b`
 
   # set width of man pages to 80 for more convenient reading
   # (( ${+MANWIDTH} )) || export MANWIDTH=80
@@ -633,7 +669,7 @@ fi
 
 # {{{ display battery status on right side of prompt via running 'BATTERY=1 zsh'
   if [[ -n "$BATTERY" ]] ; then
-     if [[ -x $(which acpi) ]] ; then
+     if check_com -c acpi ; then
         PERCENT="${(C)${(s| |)$(acpi 2>/dev/null)}[4]}"
         [[ -z "$PERCENT" ]] && PERCENT='acpi not present'
         if [[ "${PERCENT%%%}" -lt 20 ]] ; then
@@ -933,14 +969,14 @@ fi
   alias 0 &>/dev/null || functions 0 &>/dev/null || alias 0='return 0'
 
 # for really lazy people like mika:
-  type S &>/dev/null || alias S='screen'
-  type s &>/dev/null || alias s='ssh'
+  check_com S &>/dev/null || alias S='screen'
+  check_com s &>/dev/null || alias s='ssh'
 
 # get top 10 shell commands:
   alias top10='print -l ? ${(o)history%% *} | uniq -c | sort -nr | head -n 10'
 
 # truecrypt; use e.g. via 'truec /dev/ice /mnt/ice' or 'truec -i'
-  if [[ -x $(which truecrypt) ]] ; then
+  if check_com -c truecrypt ; then
      if isutfenv ; then
         alias truec='truecrypt --mount-options "rw,sync,dirsync,users,uid=1000,gid=users,umask=077,utf8" '
      else
@@ -1052,14 +1088,14 @@ Enjoy your grml system with the zsh!$res
   fi
 
 # sort installed Debian-packages by size
-  if [[ -x $(which grep-status) ]] ; then
+  if check_com -c grep-status ; then
      #a3# List installed Debian-packages sorted by size
      alias debs-by-size='grep-status -FStatus -sInstalled-Size,Package -n "install ok installed" | paste -sd "  \n" | sort -rn'
   fi
 
 # if cdrecord is a symlink (to wodim) or isn't present at all warn:
-  if [[ -L /usr/bin/cdrecord || ! -x $(which cdrecord) ]] ; then
-     if [[ -x $(which wodim) ]] ; then
+  if [[ -L /usr/bin/cdrecord ]] || ! check_com -c cdrecord ; then
+     if check_com -c wodim ; then
         alias cdrecord="echo 'cdrecord is not provided under its original name by Debian anymore.
 See #377109 in the BTS of Debian for more details.
 
@@ -1068,7 +1104,7 @@ Please use the wodim binary instead' ; r
   fi
 
 # get_tw_cli has been renamed into get_3ware
-  if [[ -x $(which get_3ware) ]] ; then
+  if check_com -c get_3ware ; then
      get_tw_cli() {
        echo 'Warning: get_tw_cli has been renamed into get_3ware. Invoking get_3ware for you.'>&2
        get_3ware
@@ -1076,7 +1112,7 @@ Please use the wodim binary instead' ; r
   fi
 
 # I hate lacking backward compatibility, so provide an alternative therefore
-  if ! [[ -x $(which apache2-ssl-certificate) ]] ; then
+  if ! check_com -c apache2-ssl-certificate ; then
      apache2-ssl-certificate(){
 
      print 'Debian does not ship apache2-ssl-certificate anymore (see #398520). :('
@@ -1266,19 +1302,19 @@ If you want to use xinit anyway please c
     fi
   }
 
-  if [[ -x $(which 915resolution) ]] ; then
+  if check_com -c 915resolution ; then
      alias 855resolution='echo -e "Please use 915resolution as resolution modify tool for Intel graphic chipset."; return -1'
   fi
 
   #a1# Output version of running grml
   alias grml-version='cat /etc/grml_version'
 
-  if [[ -x $(which rebuildfstab) ]] ; then
+  if check_com -c rebuildfstab ; then
      #a1# Rebuild /etc/fstab
      alias grml-rebuildfstab='rebuildfstab -v -r -config'
   fi
 
-  if [[ -x $(which grml-debootstrap) ]] ; then
+  if check_com -c grml-debootstrap ; then
      alias debian2hd='print "Installing debian to harddisk is possible via using grml-debootstrap." ; return 1'
   fi
 }
@@ -1341,7 +1377,7 @@ If you want to use xinit anyway please c
   }
 
   # fast manual access
-  if type -p qma &>/dev/null ; then
+  if check_com qma ; then
   #f1# View the zsh manual
      manzsh()  { qma zshall "$1" }
      compdef _man qma
@@ -1352,7 +1388,7 @@ If you want to use xinit anyway please c
      # manzsh()  { man zshall | $MYLESS -p $1 ; }
   fi
 
-  if [[ -x $(which most) ]] ; then
+  if check_com -c most ; then
   #f1# View Debian's changelog of a given package
     dchange() {
       if [[ -r /usr/share/doc/${1}/changelog.Debian.gz ]] ; then
@@ -1360,7 +1396,7 @@ If you want to use xinit anyway please c
       elif [[ -r /usr/share/doc/${1}/changelog.gz ]] ; then
          most /usr/share/doc/${1}/changelog.gz
       else
-         if type -p aptitude &>/dev/null ; then
+         if check_com -c aptitude ; then
             echo "No changelog for package $1 found, using aptitude to retrieve it."
             if isgrml ; then
               aptitude -t unstable changelog ${1}
@@ -1475,7 +1511,7 @@ If you want to use xinit anyway please c
   }
   alias help-zshglob=H-Glob
 
-  type -p qma &>/dev/null && alias ?='qma zshall'
+  check_com -c qma && alias ?='qma zshall'
 
   # grep for running process, like: 'any vim'
   any() {