diff --git a/sh/dedupe b/sh/dedupe
index be5ffd6..1c568fd 100644
--- a/sh/dedupe
+++ b/sh/dedupe
@@ -3,7 +3,7 @@
 
 dedupe() ( ### @- copy a directory, but make hard/softlinks for identical files.
 # Copyright (C) 2022 Connor Olding
-h=0 D= usage='dedupe [OPTION...] {SOURCE} {TARGET} [FILE...]
+h=0 usage='dedupe [OPTION...] {SOURCE} {TARGET} [FILE...]
 Copy files, recursively, from the source directory to the target directory,
 creating hard (or soft) links to any earlier file containing the same data.
 Optional file arguments allow for finer control of the order of files seen.
@@ -15,14 +15,14 @@ Optional file arguments allow for finer control of the order of files seen.
 This software is provided WITHOUT WARRANTY under the terms of the ISC license.'
 
 read program <<'EOF'
-BEGIN{if(!D){print U;exit 64}E=(Q="'")"\\"'\\""Q;H=(G=".")(F="/");I=" -- "Q;J="\
-[^/]*/";sub(F"?$",F,D)gsub(Q,E,D)}function C(x){if(X=system(x))exit X}{if((p=$2\
-)==B){print V;exit 65}for(r=z=i=d=B;d!=!i;i++){b=a=p;d=sub("/.*",B,a);sub(J,B,\
-p);if(a==G G)e=!sub(J,B,z);else z=a==G?z:b!=a?z a F:z a;if(e||!i&&!a){print W;\
-exit 65}}P=p=!z?H:z;if((o=O[$1])==p)next;gsub(Q,E,P);M=m=D P;gsub("/[^/]+$",B,\
-M);if(!u[M]++)C("mkdir -p"I M Q);if(o){T=split(o,t,F);S=split(p,s,F);for(i=1;t\
-[i]==s[i];i++);for(j=i;j<S;j++)r=r G H;for(j=i;j<T;j++)r=r t[j]F;r=h?o:r t[T];\
-gsub(Q,E,r);C("ln"(h?I D:" -s"I)r"' '"m Q);next}O[$1]=p;C("cp -i"I P"' '"m Q)}
+BEGIN{if(!D){exit 64}E=(Q="'")"\\"'\\""Q;H=(G=".")(F="/");I=" -- "Q;J="[^/]*/";\
+sub(F"?$",F,D)gsub(Q,E,D)}function C(x){if(X=system(x))exit X}{if((p=$2)==B)\
+{print V;exit 65}for(r=z=i=d=B;d!=!i;i++){b=a=p;d=sub("/.*",B,a);sub(J,B,p);\
+if(a==G G)e=!sub(J,B,z);else z=a==G?z:b!=a?z a F:z a;if(e||!i&&!a){print W;exit\
+ 65}}P=p=!z?H:z;if((o=O[$1])==p)next;gsub(Q,E,P);M=m=D P;gsub("/[^/]+$",B,M);\
+if(!u[M]++)C("mkdir -p"I M Q);if(o){T=split(o,t,F);S=split(p,s,F);for(i=1;t[i]\
+==s[i];i++);for(j=i;j<S;j++)r=r G H;for(j=i;j<T;j++)r=r t[j]F;r=h?o:r t[T];gsub\
+(Q,E,r);C("ln -f"(h?I D:" -s"I)r"' '"m Q);next}O[$1]=p;C("cp -p"I P"' '"m Q)}
 EOF
 
 die() { printf '\033[1mdedupe:\033[m %s\n' >&2 "$2"; exit "$1" ;}
@@ -37,11 +37,11 @@ while o="${1#-}" && [ "${#o}" != "${#1}" ] && shift
     esac; done &&
 { [ -d /tmp ] || die 72 "/tmp must be mounted" ;} &&
 { [ $# -ge 2 ] || die 64 'expected at least 2 arguments' ;} &&
-CDPATH= cd -- "$1" && shift && D="$1" && shift &&
-t="$(mktemp)" && { [ $# -eq 0 ] || sha256sum >"$t" "$@" ;} &&
+D="$(readlink -f "$2")" && CDPATH= cd -- "$1" && shift 2 && T="$(mktemp -d)" &&
+t="$T/sums" && { [ $# -eq 0 ] || sha256sum >"$t" "$@" ;} &&
 find ! -type d ! -type s -exec sha256sum -- {} + >>"$t~" &&
-sort -k2 <"$t~" >>"$t" &&
-awk -v D="$D" -v h="$h" -F'  ' "$program" <"$t"
+sort -k2 <"$t~" >>"$t" && awk -v D="$D" -v h="$h" -F'  ' "$program" <"$t"; x=$?
+! [ -d "$t" ] || rm -r "$t" && [ $x = 0 ] || die $x 'exiting after failure'
 )
 
 [ -n "${preload+-}" ] || dedupe "$@"