#!/bin/sh
# sicedit <path> <old> <new> — replace the single exact occurrence of <old>
# with <new> in <path> (edit_file semantics). Args pass losslessly via sic.
[ $# -ge 3 ] || { echo "usage: sicedit <path> <old> <new>" >&2; exit 2; }
python3 - "$1" "$2" "$3" <<'PY'
import sys
p,o,n=sys.argv[1],sys.argv[2],sys.argv[3]
s=open(p).read()
c=s.count(o)
if c==0: sys.stderr.write("sicedit: old_string not found\n"); sys.exit(1)
if c>1:  sys.stderr.write("sicedit: old_string not unique (%d matches)\n"%c); sys.exit(1)
open(p,'w').write(s.replace(o,n,1))
PY