function to check for 404s, scrap old math crap

home/zshrc

@@ -64,40 +64,11 @@ autoload -U zmv
 zmodload zsh/mathfunc
 autoload -Uz zcalc
 
-# consts are 2^-22 and 2^-21 which are simply representable in IEEE 754 floats
-zsh_math_func_slope() {
-    (( (f($1 + 0.000000238418579) - f($1 - 0.000000238418579))/0.000000476837158 ))
+isup() {
+    curl -sLI -w '%{http_code}' -o /dev/null "$1" | read -r
+    [ "${REPLY:0:1}" -eq 2 ]
 }
 
-zsh_math_func_newton() {
-    local i y=${1:-0}
-    for ((i=0; i<${2:-8}; i++)); do
-        (( y -= f(y)/slope(y) )) || return 1
-    done
-    (( y ))
-}
-
-zsh_math_func_newton2() {
-    local i x y=${1:-0} d=999999999 p=$(( 2**-${2:-32} ))
-    for ((i=0; i<32; i++)); do
-        (( x = y ))
-        (( y -= f(y)/slope(y) ))
-        (( $d < (d = abs(x - y)) )) && {
-            echo 'error: diverging, no solution' >&2
-            return
-        }
-        (( d < p )) && break
-    done
-    [ $i -eq 32 ] \
-    && echo "warning: didn't hit precision limit" >&2 \
-    || echo "iterations: $i" >&2
-    (( y ))
-}
-
-functions -M slope 1 1 zsh_math_func_slope
-functions -M newton 0 2 zsh_math_func_newton
-functions -M newton2 0 2 zsh_math_func_newton2
-
 DIRSTACKSIZE=24
 dirprev() {
     pushd -q +1