wip(commands): re-implement core commands as bash functions

Re-implement all libexec executables as bash functions, with the goal of
being able build a single standalone execuable bash script for
tmuxifier.

bin/tmuxifier

@@ -3,11 +3,12 @@ set -e
 [ -n "$TMUXIFIER_DEBUG" ] && set -x
 
 resolve_link() {
-  $(type -p greadlink readlink | head -1) $1
+  $(type -p greadlink readlink | head -1) "$1"
 }
 
 abs_dirname() {
-  local cwd="$(pwd)"
+  local cwd
+  cwd="$(pwd)"
   local path="$1"
 
   while [ -n "$path" ]; do
@@ -20,48 +21,63 @@ abs_dirname() {
   cd "$cwd"
 }
 
-if [ -z "${TMUXIFIER}" ]; then
+main() {
-  # Set TMUXIFIER relative to the "tmuxifier" executable.
+  if [ -z "${TMUXIFIER}" ]; then
-  export TMUXIFIER="$(dirname "$(abs_dirname "$0")")"
+    # Set TMUXIFIER relative to the "tmuxifier" executable.
-else
+    export TMUXIFIER="$(dirname "$(abs_dirname "$0")")"
-  # Strip any trailing slash (/) characters from TMUXIFIER variable.
+  else
-  export TMUXIFIER="${TMUXIFIER%/}"
+    # Strip any trailing slash (/) characters from TMUXIFIER variable.
-fi
+    export TMUXIFIER="${TMUXIFIER%/}"
+  fi
 
-# Load tmuxifier environment variables.
+  # Bootstrap tmuxifier.
-source "$TMUXIFIER/lib/env.sh"
+  source "$TMUXIFIER/lib/load.sh"
 
-# Add tmuxifier's internal commands to PATH.
+  # Check Tmux version.
-export PATH="$TMUXIFIER/libexec:$PATH"
+  export TMUXIFIER_MIN_TMUX_VERSION="1.6"
+  if [ "$(tmuxifier-tmux-version "$TMUXIFIER_MIN_TMUX_VERSION")" == "<" ]; then
+    echo -e "ERROR: Tmuxifier requires Tmux v${TMUXIFIER_MIN_TMUX_VERSION}" \
+      "or newer. You have v$(tmuxifier-tmux-version)." >&2
+    exit 1
+  fi
 
-# Check Tmux version.
+  # Get command and shift arguments.
-export TMUXIFIER_MIN_TMUX_VERSION="1.6"
+  local command="$1"
-if [ "$(tmuxifier-tmux-version "$TMUXIFIER_MIN_TMUX_VERSION")" == "<" ]; then
+  shift 1
-  echo -e "ERROR: Tmuxifier requires Tmux v${TMUXIFIER_MIN_TMUX_VERSION}" \
-       "or newer. You have v$(tmuxifier-tmux-version)." >&2
-  exit 1
-fi
 
-# Parse given command
+  # Resolve to full command name if an alias is given.
-command="$1"
+  command="$(tmuxifier-alias "$command" || echo "$command")"
-case "$command" in
-  "" | "-h" | "--help" )
-    echo -e "tmuxifier $(tmuxifier-version)\n$(tmuxifier-help)" >&2
-    ;;
 
-  "-v" | "--version" )
+  case "$command" in
-    tmuxifier-version
+    "" | "-h" | "--help")
-    ;;
+      echo -e "tmuxifier $(tmuxifier-version)\n$(tmuxifier-help)" >&2
+      ;;
 
-  * )
+    "-v" | "--version")
-    ! command_path="$(tmuxifier-resolve-command-path "$command")"
+      tmuxifier-version
+      ;;
 
-    if [ -z "$command_path" ]; then
+    *)
-      echo "tmuxifier: no such command '$command'" >&2
+      local command_path
-      exit 1
+      local func_name
-    fi
 
-    shift 1
+      func_name="tmuxifier-$command"
-    exec "$command_path" "$@"
+
-    ;;
+      # Check if command is available as a function.
-esac
+      if declare -f "$func_name" > /dev/null; then
+        "$func_name" "$@"
+      else
+        # Fall back to libexec executable.
+        command_path="$(tmuxifier-resolve-command-path "$command")" || true
+        if [ -z "$command_path" ]; then
+          echo "tmuxifier: no such command '$command'" >&2
+          exit 1
+        fi
+
+        exec "$command_path" "$@"
+      fi
+      ;;
+  esac
+}
+
+main "$@"

completion/tmuxifier.bash

@@ -3,11 +3,11 @@ _tmuxifier() {
   local word="${COMP_WORDS[COMP_CWORD]}"
 
   if [ "$COMP_CWORD" -eq 1 ]; then
-    COMPREPLY=( $(compgen -W "$(tmuxifier commands)" -- "$word") )
+    COMPREPLY=($(compgen -W "$(tmuxifier commands)" -- "$word"))
   else
     local command="${COMP_WORDS[1]}"
     local completions="$(tmuxifier completions "$command")"
-    COMPREPLY=( $(compgen -W "$completions" -- "$word") )
+    COMPREPLY=($(compgen -W "$completions" -- "$word"))
   fi
 }
 

lib/commands/alias.sh

@@ -0,0 +1,56 @@
+# Resolve a tmuxifier command alias to its full command name.
+#
+# Usage:
+#   tmuxifier-alias <alias>
+#
+# Arguments:
+#   $1 - Alias to resolve
+#
+# Output:
+#   The full command name if alias is recognized, empty otherwise.
+#
+# Returns:
+#   0 - Alias was recognized
+#   1 - Alias was not recognized
+tmuxifier-alias() {
+  # Provide tmuxifier help
+  if calling-help "$@"; then
+    echo "usage: tmuxifier alias <alias>
+
+Resolve a command alias to it's full name."
+    return
+  fi
+
+  case "$1" in
+    "session" | "ses" | "s")
+      echo "load-session"
+      ;;
+    "window" | "win" | "w")
+      echo "load-window"
+      ;;
+    "new-ses" | "nses" | "ns")
+      echo "new-session"
+      ;;
+    "new-win" | "nwin" | "nw")
+      echo "new-window"
+      ;;
+    "edit-ses" | "eses" | "es")
+      echo "edit-session"
+      ;;
+    "edit-win" | "ewin" | "ew")
+      echo "edit-window"
+      ;;
+    "l")
+      echo "list"
+      ;;
+    "list-ses" | "lses" | "ls")
+      echo "list-sessions"
+      ;;
+    "list-win" | "lwin" | "lw")
+      echo "list-windows"
+      ;;
+    *)
+      return 1
+      ;;
+  esac
+}

lib/commands/resolve-command-path.sh

@@ -0,0 +1,43 @@
+# Resolve the absolute path to a tmuxifier command or alias.
+#
+# Usage:
+#   tmuxifier-resolve-command-path <command_or_alias>
+#
+# Arguments:
+#   $1 - Command name or alias to resolve
+#
+# Output:
+#   The absolute path to the command executable, or empty if not found.
+#
+# Returns:
+#   0 - Command was found
+#   1 - Command was not found
+tmuxifier-resolve-command-path() {
+  # Provide tmuxifier help
+  if calling-help "$@"; then
+    echo "usage: tmuxifier resolve-command-path <command_or_alias>
+
+Outputs the absolute path to the given command or command alias."
+    return
+  fi
+
+  local command_path=""
+
+  if [ -n "$1" ]; then
+    # Look for executable file, not functions.
+    command_path="$(type -P "tmuxifier-$1" 2> /dev/null)" || true
+    if [ -z "$command_path" ]; then
+      local resolved
+      resolved="$(tmuxifier-alias "$1")"
+      if [ -n "$resolved" ]; then
+        command_path="$(type -P "tmuxifier-$resolved" 2> /dev/null)" || true
+      fi
+    fi
+  fi
+
+  if [ -n "$command_path" ]; then
+    echo "$command_path"
+  else
+    return 1
+  fi
+}

lib/commands/tmux-version.sh

@@ -0,0 +1,63 @@
+# Enable extended globbing for version string cleanup.
+shopt -s extglob
+
+# Output current Tmux version, or compare against a target version.
+#
+# Usage:
+#   tmuxifier-tmux-version             # Outputs current Tmux version
+#   tmuxifier-tmux-version "1.9"       # Outputs "=", "<", or ">"
+#
+# Arguments:
+#   $1 - Optional target version to compare against
+#
+# Output:
+#   Without arguments: The current Tmux version string
+#   With target version: One of "=", "<", or ">" indicating if the current
+#                        Tmux version is equal to, less than, or greater than
+#                        the target version.
+#
+# Returns:
+#   0 - Always succeeds
+tmuxifier-tmux-version() {
+  # Provide tmuxifier help
+  if calling-help "$@"; then
+    echo "usage: tmuxifier tmux-version [<target-version>]
+
+Outputs current Tmux version. If given optional target-version it outputs one
+of three possible characters indicating if the current Tmux version number is
+equal to, less than, or greater than the <target-version>.
+
+The three possible outputs are \"=\", \"<\", and \">\"."
+    return
+  fi
+
+  local version
+  version="$(tmux -V)"
+  version="${version/tmux /}"
+
+  # Fix for tmux next-* versions
+  version="${version/next-/}"
+
+  if [ -z "$1" ]; then
+    echo "$version"
+    return
+  fi
+
+  if [ "$version" == "master" ]; then
+    # When version string is "master", tmux was compiled from source, and we
+    # assume it's later than whatever the <target-version> is.
+    echo '>'
+  else
+    # Fix for "1.9a" version comparison, as vercomp() can only deal with
+    # purely numeric version numbers.
+    version="${version//+([a-zA-Z])/}"
+
+    local result
+    vercomp "$version" "$1" && result=$? || result=$?
+    case $result in
+      0) echo '=' ;;
+      1) echo '>' ;;
+      2) echo '<' ;;
+    esac
+  fi
+}

lib/layout-helpers.sh

@@ -140,7 +140,7 @@ balance_windows_horizontal() {
 #
 synchronize_on() {
   tmuxifier-tmux set-window-option -t "$session:${1:-$window}" \
-                 synchronize-panes on
+    synchronize-panes on
 }
 
 # Turn off synchronize-panes in a window.
@@ -150,7 +150,7 @@ synchronize_on() {
 #
 synchronize_off() {
   tmuxifier-tmux set-window-option -t "$session:${1:-$window}" \
-                 synchronize-panes off
+    synchronize-panes off
 }
 
 # Send/paste keys to the currently active pane/window.
@@ -214,8 +214,8 @@ load_window() {
     if [ $# -gt 1 ]; then
       window="$2"
     else
-      window="${1/%.window.sh}"
+      window="${1/%.window.sh/}"
-      window="${window/%.sh}"
+      window="${window/%.sh/}"
     fi
     source "$file"
     window=
@@ -258,8 +258,8 @@ load_session() {
   if [ $# -gt 1 ]; then
     session="$2"
   else
-    session="${1/%.session.sh}"
+    session="${1/%.session.sh/}"
-    session="${session/%.sh}"
+    session="${session/%.sh/}"
   fi
 
   set_default_path=true
@@ -308,7 +308,7 @@ initialize_session() {
 
       $set_default_path && tmuxifier-tmux \
         set-option -t "$session:" \
-        default-path "$session_root" 1>/dev/null
+        default-path "$session_root" 1> /dev/null
     fi
 
   # Tmux 1.9 and later.
@@ -344,13 +344,12 @@ initialize_session() {
 # created, but already existed, then we'll need to specifically switch to it.
 #
 finalize_and_go_to_session() {
-  ! tmuxifier-tmux kill-window -t "$session:999" 2>/dev/null
+  ! tmuxifier-tmux kill-window -t "$session:999" 2> /dev/null
   if [[ "$(tmuxifier-current-session)" != "$session" ]]; then
     __go_to_session
   fi
 }
 
-
 #
 # Internal functions
 #
@@ -368,7 +367,7 @@ __expand_path() {
 
 __get_first_window_index() {
   local index=$(tmuxifier-tmux list-windows -t "$session:" \
-    -F "#{window_index}" 2>/dev/null)
+    -F "#{window_index}" 2> /dev/null)
 
   if [ -n "$index" ]; then
     echo "$index" | head -1
@@ -379,10 +378,10 @@ __get_first_window_index() {
 
 __get_current_window_index() {
   local lookup=$(tmuxifier-tmux list-windows -t "$session:" \
-    -F "#{window_active}:#{window_index}" 2>/dev/null | grep "^1:")
+    -F "#{window_active}:#{window_index}" 2> /dev/null | grep "^1:")
 
   if [ -n "$lookup" ]; then
-    echo "${lookup/1:}"
+    echo "${lookup/1:/}"
   fi
 }
 
@@ -408,7 +407,7 @@ __go_to_window_or_session_path() {
 
   # local window_or_session_root=${window_root-$session_root}
   if [ -n "$target_path" ]; then
-    run_cmd "cd \"$target_path\""
+    run_cmd " cd \"$target_path\""
-    run_cmd "clear"
+    run_cmd " clear"
   fi
 }

lib/load.sh

@@ -0,0 +1,17 @@
+# Setup layout path.
+if [ -z "${TMUXIFIER_LAYOUT_PATH}" ]; then
+  export TMUXIFIER_LAYOUT_PATH="${TMUXIFIER}/layouts"
+else
+  export TMUXIFIER_LAYOUT_PATH="${TMUXIFIER_LAYOUT_PATH%/}"
+fi
+
+# Add tmuxifier's internal commands to PATH.
+export PATH="$TMUXIFIER/libexec:$PATH"
+
+# Load utility functions.
+source "$TMUXIFIER/lib/util.sh"
+
+# Load command functions from lib/commands/ directory directly.
+source "$TMUXIFIER/lib/commands/alias.sh"
+source "$TMUXIFIER/lib/commands/resolve-command-path.sh"
+source "$TMUXIFIER/lib/commands/tmux-version.sh"

lib/util.sh

@@ -1,11 +1,11 @@
 calling-help() {
-  if [[ " $@ " != *" --help "* ]] && [[ " $@ " != *" -h "* ]]; then
+  if [[ " $* " != *" --help "* ]] && [[ " $* " != *" -h "* ]]; then
     return 1
   fi
 }
 
 calling-complete() {
-  if [[ " $@ " != *" --complete "* ]]; then
+  if [[ " $* " != *" --complete "* ]]; then
     return 1
   fi
 }

libexec/tmuxifier-alias

@@ -1,46 +1,6 @@
 #! /usr/bin/env bash
-set -e
 [ -n "$TMUXIFIER_DEBUG" ] && set -x
 
-# Load internal utility functions.
+source "$TMUXIFIER/lib/load.sh"
-source "$TMUXIFIER/lib/util.sh"
 
-# Provide tmuxifier help
+tmuxifier-alias "$@"
-if calling-help "$@"; then
-  echo "usage: tmuxifier alias <alias>
-
-Resolve a command alias to it's full name."
-  exit
-fi
-
-case "$1" in
-  "session" | "ses" | "s" )
-    echo "load-session"
-    ;;
-  "window" | "win" | "w" )
-    echo "load-window"
-    ;;
-  "new-ses" | "nses" | "ns" )
-    echo "new-session"
-    ;;
-  "new-win" | "nwin" | "nw" )
-    echo "new-window"
-    ;;
-  "edit-ses" | "eses" | "es" )
-    echo "edit-session"
-    ;;
-  "edit-win" | "ewin" | "ew" )
-    echo "edit-window"
-    ;;
-  "l" )
-    echo "list"
-    ;;
-  "list-ses" | "lses" | "ls" )
-    echo "list-sessions"
-    ;;
-  "list-win" | "lwin" | "lw" )
-    echo "list-windows"
-    ;;
-  * )
-    exit 1
-esac

libexec/tmuxifier-commands

@@ -16,7 +16,8 @@ fi
 
 shopt -s nullglob
 
-{ for path in ${PATH//:/$'\n'}; do
+{
+  for path in ${PATH//:/$'\n'}; do
     for command in "${path}/tmuxifier-"*; do
       command="${command##*tmuxifier-}"
       echo "$command"

libexec/tmuxifier-completions

@@ -20,11 +20,11 @@ if calling-complete "$@"; then
 fi
 
 has-completions() {
-  grep -i "^# Provide tmuxifier completions" "$1" >/dev/null
+  grep -i "^# Provide tmuxifier completions" "$1" > /dev/null
 }
 
 if [ -z "$1" ]; then
-  echo "$(tmuxifier-help completions $@)" >&2
+  tmuxifier-help completions "$@" >&2
   exit 1
 fi
 

libexec/tmuxifier-current-session

@@ -14,8 +14,8 @@ Outputs the name of the current Tmux session."
 fi
 
 if [ -n "$TMUX" ]; then
-  for item in $(tmuxifier-tmux list-pane -F "#{session_name}");do
+  for item in $(tmuxifier-tmux list-pane -F "#{session_name}"); do
-    echo $item
+    echo "$item"
     exit 0
   done
 fi

libexec/tmuxifier-edit-session

@@ -22,7 +22,7 @@ if calling-complete "$@"; then
 fi
 
 if [ -z "$1" ]; then
-  echo "$(tmuxifier-help edit-session $@)" >&2
+  tmuxifier-help edit-session "$@" >&2
   exit 1
 fi
 

libexec/tmuxifier-edit-window

@@ -22,7 +22,7 @@ if calling-complete "$@"; then
 fi
 
 if [ -z "$1" ]; then
-  echo "$(tmuxifier-help edit-window $@)" >&2
+  tmuxifier-help edit-window "$@" >&2
   exit 1
 fi
 

libexec/tmuxifier-help

@@ -18,7 +18,7 @@ if calling-complete "$@"; then
 fi
 
 has-help() {
-  grep -i "^# Provide tmuxifier help" "$1" >/dev/null
+  grep -i "^# Provide tmuxifier help" "$1" > /dev/null
 }
 
 if [ -z "$1" ]; then

libexec/tmuxifier-init

@@ -14,25 +14,25 @@ if [ -z "$shell" ]; then
 fi
 
 case "$shell" in
-  bash )
+  bash)
     profile='~/.bash_profile'
     ;;
-  zsh )
+  zsh)
     profile='~/.zshrc'
     ;;
-  ksh )
+  ksh)
     profile='~/.profile'
     ;;
-  csh )
+  csh)
     profile='~/.cshrc'
     ;;
-  tcsh )
+  tcsh)
     profile='~/.tcshrc'
     ;;
-  fish )
+  fish)
     profile='~/.config/fish/config.fish'
     ;;
-  * )
+  *)
     profile='shell init file'
     ;;
 esac
@@ -45,15 +45,15 @@ Load Tmuxifier by adding the following to your ${profile}:
 "
 
   case "$shell" in
-    csh | tcsh )
+    csh | tcsh)
       echo "    eval \`tmuxifier init -\`
 "
       ;;
-    fish )
+    fish)
       echo "    eval (tmuxifier init -)
 "
       ;;
-    * )
+    *)
       echo "    eval \"\$(tmuxifier init -)\"
 "
       ;;
@@ -64,17 +64,17 @@ Load Tmuxifier by adding the following to your ${profile}:
 fi
 
 # Print help if "-" argument is not given
-if [[ " $@ " != *" - "* ]]; then
+if [[ " $* " != *" - "* ]]; then
-  echo "$(tmuxifier-help init $@)" >&2
+  tmuxifier-help init "$@" >&2
   exit 1
 fi
 
 case "$shell" in
-  csh | tcsh )
+  csh | tcsh)
     echo "setenv TMUXIFIER \"$TMUXIFIER\";"
     echo "source \"\$TMUXIFIER/init.tcsh\";"
     ;;
-  fish )
+  fish)
     echo "set -gx TMUXIFIER \"$TMUXIFIER\";"
     # fish shell 2.0.0 does not have the source alias
     if [[ $(fish --version 2>&1 | awk -F'version ' '{print $2}') = '2.0.0' ]]; then
@@ -83,7 +83,7 @@ case "$shell" in
       echo "source \"\$TMUXIFIER/init.fish\";"
     fi
     ;;
-  * )
+  *)
     echo "export TMUXIFIER=\"$TMUXIFIER\";"
     echo "source \"\$TMUXIFIER/init.sh\";"
     ;;

libexec/tmuxifier-load-session

@@ -30,7 +30,7 @@ if calling-complete "$@"; then
 fi
 
 if [ -z "$1" ]; then
-  echo "$(tmuxifier-help load-session $@)" >&2
+  tmuxifier-help load-session "$@" >&2
   exit 1
 fi
 

libexec/tmuxifier-load-window

@@ -26,14 +26,14 @@ if calling-complete "$@"; then
 fi
 
 if [ -z "$1" ]; then
-  echo "$(tmuxifier-help load-window $@)" >&2
+  tmuxifier-help load-window "$@" >&2
   exit 1
 fi
 
 # Load runtime functions.
 source "$TMUXIFIER/lib/runtime.sh"
 
-if [ ! -z $TMUX ]; then
+if [ ! -z "$TMUX" ]; then
   session="$(tmuxifier-current-session)"
   load_window "$1"
 else

libexec/tmuxifier-new-session

@@ -22,7 +22,7 @@ if calling-complete "$@"; then
 fi
 
 if [ -z "$1" ]; then
-  echo "$(tmuxifier-help new-session $@)" >&2
+  tmuxifier-help new-session "$@" >&2
   exit 1
 fi
 

libexec/tmuxifier-new-window

@@ -22,7 +22,7 @@ if calling-complete "$@"; then
 fi
 
 if [ -z "$1" ]; then
-  echo "$(tmuxifier-help new-window $@)" >&2
+  tmuxifier-help new-window "$@" >&2
   exit 1
 fi
 

libexec/tmuxifier-resolve-command-path

@@ -1,30 +1,6 @@
 #! /usr/bin/env bash
-set -e
 [ -n "$TMUXIFIER_DEBUG" ] && set -x
 
-# Load internal utility functions.
+source "$TMUXIFIER/lib/load.sh"
-source "$TMUXIFIER/lib/util.sh"
 
-# Provide tmuxifier help
+tmuxifier-resolve-command-path "$@"
-if calling-help "$@"; then
-  echo "usage: tmuxifier resolve-command-path <command_or_alias>
-
-Outputs the absolute path to the given command or command alias."
-  exit
-fi
-
-if [ -n "$1" ]; then
-  ! command_path="$(command -v "tmuxifier-$1")"
-  if [ -z "$command_path" ]; then
-    resolved="$(tmuxifier-alias "$1")"
-    if [ -n "$resolved" ]; then
-      ! command_path="$(command -v "tmuxifier-$resolved")"
-    fi
-  fi
-fi
-
-if [ -n "$command_path" ]; then
-  echo "$command_path"
-else
-  exit 1
-fi

libexec/tmuxifier-tmux-version

@@ -1,70 +1,6 @@
 #! /usr/bin/env bash
-shopt -s extglob
 [ -n "$TMUXIFIER_DEBUG" ] && set -x
 
-# Load internal utility functions.
+source "$TMUXIFIER/lib/load.sh"
-source "$TMUXIFIER/lib/util.sh"
 
-# Provide tmuxifier help
+tmuxifier-tmux-version "$@"
-if calling-help "$@"; then
-  echo "usage: tmuxifier tmux-version [<target-version>]
-
-Outputs current Tmux version. If given optional target-version it outputs one
-of three possible characters indicating if the current Tmux version number is
-equal to, less than, or greater than the <target-version>.
-
-The three possible outputs are \"=\", \"<\", and \">\"."
-  exit
-fi
-
-# The vercomp() function is shamelessly ripped/borrowed from the following
-# StackOverflow answer: http://stackoverflow.com/a/4025065/42146
-vercomp () {
-  if [[ $1 == $2 ]]; then return 0; fi
-
-  local IFS=.
-  local i ver1=($1) ver2=($2)
-
-  # fill empty fields in ver1 with zeros
-  for ((i=${#ver1[@]}; i<${#ver2[@]}; i++)); do ver1[i]=0; done
-
-  for ((i=0; i<${#ver1[@]}; i++)); do
-    # fill empty fields in ver2 with zeros
-    if [[ -z ${ver2[i]} ]]; then ver2[i]=0; fi
-
-    if ((10#${ver1[i]} > 10#${ver2[i]})); then
-      return 1
-    elif ((10#${ver1[i]} < 10#${ver2[i]})); then
-      return 2
-    fi
-  done
-  return 0
-}
-
-version=$(tmux -V)
-version=${version/tmux /}
-
-# Fix for tmux next-* versions
-version=${version/next-/}
-
-if [ -z "$1" ]; then
-  echo "$version"
-  exit
-fi
-
-if [ "$version" == "master" ]; then
-  # When version string is "master", tmux was compiled from source, and we
-  # assume it's later than whatever the <target-version> is.
-  echo '>'
-else
-  # Fix for "1.9a" version comparison, as vercomp() can only deal with
-  # purely numeric version numbers.
-  version=${version//+([a-zA-Z])/}
-
-  vercomp "$version" "$1"
-  case $? in
-    0) echo '=';;
-    1) echo '>';;
-    2) echo '<';;
-  esac
-fi