shell: have, path_(append|prepend|remove)

- have: command -v shorthand
- path_append: appends dir to PATH
- path_prepend: prepends dir to PATH
- path_remove: removes dir from PATH

config/exports-apps

@@ -2,6 +2,7 @@
 # shellcheck shell=bash
 # shellcheck enable=external-sources
 # vim: filetype=zsh
+source "$DOTFILES/scripts/shared.sh"
 
 # Antigen configuration
 # https://github.com/zsh-users/antigen/wiki/Configuration
@@ -11,61 +12,62 @@ export ANTIGEN_PLUGIN_RECEIPT_F=".local/share/antigen/antigen_plugin_lastupdate"
 
 # Ansible configuration
 # https://docs.ansible.com/ansible/latest/reference_appendices/config.html
-if hash ansible 2> /dev/null; then
+have ansible && {
   export ANSIBLE_HOME="$XDG_CONFIG_HOME/ansible"
   export ANSIBLE_CONFIG="$XDG_CONFIG_HOME/ansible.cfg"
   export ANSIBLE_GALAXY_CACHE_DIR="$XDG_CACHE_HOME/ansible/galaxy_cache"
   x-dc "$ANSIBLE_HOME"
   x-dc "$ANSIBLE_GALAXY_CACHE_DIR"
-fi
+}
 
 # composer, https://getcomposer.org/
-if command -v composer &> /dev/null; then
+have composer && {
   export COMPOSER_HOME="$XDG_STATE_HOME/composer"
   export COMPOSER_BIN="$COMPOSER_HOME/vendor/bin"
   export PATH="$COMPOSER_BIN:$PATH"
-fi
+}
 
 # docker, https://docs.docker.com/engine/reference/commandline/cli/
-if command -v docker &> /dev/null; then
+have docker && {
   export DOCKER_CONFIG="$XDG_CONFIG_HOME/docker"
   x-dc "$DOCKER_CONFIG"
-fi
+}
 
 # ffmpeg
-if hash ffmpeg 2> /dev/null; then
+have ffmpeg && {
   export FFMPEG_DATADIR="$XDG_CONFIG_HOME/ffmpeg"
   x-dc "$FFMPEG_DATADIR"
-fi
+}
 
 # gcloud
-if hash gcloud 2> /dev/null; then
+have gcloud && {
   GCLOUD_LOC=$(gcloud info --format="value(installation.sdk_root)" --quiet)
   [[ -f "$GCLOUD_LOC/path.zsh.inc" ]] && builtin source "$GCLOUD_LOC/path.zsh.inc"
   [[ -f "$GCLOUD_LOC/completion.zsh.inc" ]] && builtin source "$GCLOUD_LOC/completion.zsh.inc"
-fi
+}
 
 # gem, rubygems
-if command -v gem &> /dev/null; then
+have gem && {
   export GEM_HOME="$XDG_STATE_HOME/gem"
   export GEM_PATH="$XDG_STATE_HOME/gem"
   export PATH="$GEM_HOME/bin:$PATH"
-fi
+  path_append "$GEM_PATH/bin"
+}
 
 # If we have go packages, include them to the PATH
-if command -v go &> /dev/null; then
+have go && {
   export GOPATH="$XDG_DATA_HOME/go"
   export GOBIN="$XDG_BIN_HOME"
   x-dc "$GOPATH"
-fi
+}
 
 # irssi
-if hash irssi 2> /dev/null; then
+have irssi && {
   # These variables are used in ./alias with --config and --home
   export IRSSI_CONFIG_HOME="$XDG_CONFIG_HOME/irssi"
   export IRSSI_CONFIG_FILE="$IRSSI_CONFIG_HOME/config"
   x-dc "$IRSSI_CONFIG_HOME"
-fi
+}
 
 # nvm, the node version manager
 export NVM_LAZY_LOAD=true
@@ -76,21 +78,21 @@ export NVM_DIR="$XDG_CONFIG_HOME/nvm"
 [ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion" # This loads nvm bash_completion
 
 # op (1Password cli) is present
-if hash op 2> /dev/null; then
+have op && {
   export OP_CACHE="$XDG_STATE_HOME/1password"
   x-dc "$OP_CACHE"
   eval "$(op completion zsh)"
   compdef _op op
-fi
+}
 
 # pyenv, python environments
-if command -v pyenv &> /dev/null; then
+have pyenv && {
   export PYENV_ROOT="$XDG_STATE_HOME/pyenv"
   x-dc "$PYENV_ROOT"
-  export PATH="$PYENV_ROOT/bin:$PATH"
+  path_append "$PYENV_ROOT/bin"
 
   eval "$(pyenv init -)"
-fi
+}
 
 # wakatime, https://github.com/wakatime/wakatime-cli
 export WAKATIME_HOME="$XDG_STATE_HOME/wakatime"
@@ -104,4 +106,3 @@ export _Z_DATA="$XDG_STATE_HOME/z"
 export ANDROID_HOME="$XDG_DATA_HOME/android"
 export GNUPGHOME="$XDG_DATA_HOME/gnupg"
 export SCREENRC="$XDG_CONFIG_HOME/misc/screenrc"
-