initial commit

.config/zsh/lib/alternatives.zsh

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+#!/bin/zsh
+
+## alternatives list is pipe-separated list of commands/binaries
+
+## find (first) candidate in alternatives
+## $1 - alternatives list
+## $2 - arguments to test command (USE WITH CAUTION!)
+z-alt-find() {
+    local i c r t
+    local -a v a
+
+    v=( ${(@s:|:)1} )
+    [ ${#v} = 0 ] && v=( "$1" )
+    for i ( $v ) ; do
+        a=( ${(@s: :)i} )
+
+        c=$(which "${a[1]}")
+        [ -z "$c" ] && continue
+
+        # r=$(readlink -f "$c" 2>/dev/null)
+        # [ -z "$r" ] && continue
+        # a[1]="$r"
+
+        if [ -n "$2" ] ; then
+            t="$a $2"
+            command ${(@s: :)t} </dev/null &>/dev/null || continue
+        fi
+
+        echo "${a[@]}"
+        return 0
+    done
+
+    return 127
+}
+
+## set function alias for alternative (one-time static resolve)
+## $1 - function name
+## $2 - alternatives list
+## $3 - command wrapper
+## $4 - function prologue
+## $5 - function epilogue
+z-alt-set-static() {
+    local n t a r
+    local -a s
+    n="$1" ; t=''
+    if [[ "$n" =~ '\|' ]] ; then
+        t=${n:${MBEGIN}} ; n=${n:0:${MBEGIN}-1}
+    fi
+    a=$(z-alt-find "$2" "$t")
+    if [ -n "$a" ] ; then
+        r=0
+        [ -n "$4" ] && s+=( "$4 ;" )
+        [ -n "$3" ] && s+=( "$3" )
+        s+=( "command $a \"\$@\" || return 127" )
+        [ -n "$5" ] && s+=( "; $5" )
+    else
+        r=127
+        s+=( 'return 127' )
+    fi
+    eval "$n () { ${s[@]} ; } ; typeset -g $n"
+    return $r
+}
+
+## set function alias for alternative (dynamic resolve)
+## $1 - function name
+## $2 - alternatives list
+## $3 - command wrapper
+## $4 - function prologue
+## $5 - function epilogue
+z-alt-set-dynamic() {
+    local n t
+    local -a s
+    n="$1" ; t=''
+    if [[ "$n" =~ '\|' ]] ; then
+        t=${n:${MBEGIN}} ; n=${n:0:${MBEGIN}-1}
+    fi
+    [ -n "$4" ] && s+=( "$4 ;" )
+    s+=( 'local a=$(z-alt-find' "${(qq)2}" "${t:+' $t'} ) ;" )
+    [ -n "$3" ] && s+=( "$3" )
+    s+=( 'command ${(@s: :)a} "$@" || return 127' )
+    [ -n "$5" ] && s+=( "; $5" )
+    eval "$n () { ${s[@]} ; } ; typeset -g $n"
+}