Check if program exists before configuring

Check if program is present before configuring it (make configuration
portable)

Author: nevalsar

zsh/.zshenv

@@ -1,30 +1,27 @@
 # https://zsh.sourceforge.io/Contrib/startup/users/debbiep/dot.zshenv
 # Function to remove non-existent directories from array.
 rationalize-path () {
-  local element
-  local build
-  build=()
-  # Evil quoting to survive an eval and to make sure that
-  # this works even with variables containing IFS characters, if I'm
-  # crazy enough to setopt shwordsplit.
-  eval '
-  foreach element in "$'"$1"'[@]"
-  do
-    if [[ -d "$element" ]]
-    then
-      build=("$build[@]" "$element")
-    fi
-  done
-  '"$1"'=( "$build[@]" )
-  '
+    local element
+    local build
+    build=()
+    # Evil quoting to survive an eval and to make sure that
+    # this works even with variables containing IFS characters, if I'm
+    # crazy enough to setopt shwordsplit.
+    eval '
+    foreach element in "$'"$1"'[@]"
+    do
+        if [[ -d "$element" ]]
+        then
+            build=("$build[@]" "$element")
+        fi
+    done
+    '"$1"'=( "$build[@]" )
+    '
 }
 
 # Set up additional paths
 path+=(
-    ~/.npm-global/bin
     ~/.local/bin
-    ~/.linuxbrew/bin
-    ~/.linuxbrew/sbin
 )
 
 rationalize-path path
@@ -33,11 +30,6 @@ typeset -U path
 
 # Set INFOPATH
 typeset -T INFOPATH infopath
-infopath+=(
-    ~/.linuxbrew/share/info
-)
-rationalize-path infopath
-typeset -U infopath
 
 # Set MANPATH
 typeset -T MANPATH manpath
@@ -47,20 +39,47 @@ manpath+=(
 rationalize-path manpath
 typeset -U manpath
 
-source "$HOME/.cargo/env"
+if [ ! -f $HOME/.cargo/env ]
+then
+    source "$HOME/.cargo/env"
+fi
+
+# Set up pyenv
+if (( $+commands[pyenv] ))
+then
+    export PYENV_ROOT="$HOME/.pyenv"
+    path=($PYENV_ROOT/bin "$path[@]")
+    eval "$(pyenv init --path)"
+    eval "$(pyenv init -)"
+    eval "$(pyenv virtualenv-init -)"
+fi
+
+# Set up linuxbrew
+if (( $+commands[brew]  ))
+then
+    export HOMEBREW_PREFIX=~/.linuxbrew
+    export HOMEBREW_CELLAR=~/.linuxbrew/Cellar
+    export HOMEBREW_REPOSITORY=~/.linuxbrew/Homebrew
+    export HOMEBREW_SHELLENV_PREFIX=~/.linuxbrew
 
-# Set up Brew
-export HOMEBREW_PREFIX=~/.linuxbrew
-export HOMEBREW_CELLAR=~/.linuxbrew/Cellar
-export HOMEBREW_REPOSITORY=~/.linuxbrew/Homebrew
-export HOMEBREW_SHELLENV_PREFIX=~/.linuxbrew
+    path+=(
+        ~/.linuxbrew/bin
+        ~/.linuxbrew/sbin
+    )
+    rationalize-path path
+    typeset -U path
+
+    infopath+=(
+        ~/.linuxbrew/share/info
+    )
+    rationalize-path infopath
+    typeset -U infopath
+fi
+
+# Set up cuda
+path=(/usr/local/cuda-11.6/bin "$path[@]")
+export PYENV_VIRTUALENV_DISABLE_PROMPT=1
 
 # Source aliases
 source $HOME/.aliases.zsh
 
-# Set up pyenv
-export PYENV_ROOT="$HOME/.pyenv"
-path=($PYENV_ROOT/bin "$path[@]")
-eval "$(pyenv init --path)"
-eval "$(pyenv init -)"
-eval "$(pyenv virtualenv-init -)"

zsh/.zshrc

@@ -4,6 +4,7 @@
     git clone --depth 1 -- \
         https://github.com/marlonrichert/zsh-snap.git ~/.znap/zsh-snap
 
+# Load znap
 source ~/.znap/zsh-snap/znap.zsh
 
 # Enable menu-driven completion
@@ -31,13 +32,21 @@ znap eval trapd00r/LS_COLORS "$( whence -a dircolors gdircolors ) -b LS_COLORS"
 znap source zsh-users/zsh-autosuggestions
 znap source zsh-users/zsh-completions
 znap source esc/conda-zsh-completion
-znap source DarrinTisdale/zsh-aliases-exa
+
+# Install exa aliases only if exa is installed
+if (( $+commands[exa] ))
+then
+    znap source DarrinTisdale/zsh-aliases-exa
+fi
 ### End install plugins
 
 ### Configure completions
 #
-znap fpath _rustup 'rustup completions zsh'
-znap fpath _cargo 'rustup completions zsh cargo'
+if (( $+commands[rustup] ))
+then
+    znap fpath _rustup 'rustup completions zsh'
+    znap fpath _cargo 'rustup completions zsh cargo'
+fi
 ### End configure completions
 
 ### Functions
@@ -92,15 +101,15 @@ unset __conda_setup
 ### End configure conda
 
 ### Configure junegunn/fzf
-
+# https://github.com/junegunn/fzf
+#
 export FZF_DEFAULT_COMMAND="fd . $HOME"
 export FZF_CTRL_T_COMMAND="$FZF_DEFAULT_COMMAND"
 export FZF_ALT_C_COMMAND="fd -t d . $HOME"
 
 # Press CTRL-Y to copy the line to clipboard and aborts fzf
 export FZF_DEFAULT_OPTS="--bind 'ctrl-w:execute-silent(echo {} | xclip -i -sel clip)+abort'"
 
-#
 # Source key binding and completion
 source /usr/share/doc/fzf/examples/key-bindings.zsh
 source /usr/share/doc/fzf/examples/completion.zsh