[zsh] add a few useful aliases and functions

zsh/aliases.zsh

@@ -2,8 +2,12 @@
 
 # this alias removes leading dollar sign (useful when copying code from Stackoverflow)
 alias '$'=''
-# this alias allows aliases to work with sudo
+
+# the following aliases allow alias expansion in common programs which take
+# commands as their arguments
 alias sudo='sudo '
+alias watch='watch '
+alias xargs='xargs '
 
 alias history='fc -i -l 1'
 

zsh/functions.zsh

@@ -1,5 +1,6 @@
 #!/usr/bin/env zsh
 
+
 count() { echo "$#"; }
 
 bytecount() { wc -c "$@" | numfmt --to=iec-i; }
@@ -72,3 +73,11 @@ git_current_branch() {
   )" || return
   echo "${ref#refs/heads/}"
 }
+
+date-fmt-iso() {
+  date --utc +'%Y-%m-%dT%H:%M:%SZ' "$@"
+}
+
+date-fmt-compact() {
+  date --utc +'%Y%m%d%H%M%S' "$@"
+}