ref: 878abeeaad1929387d2f527989f2c17d385a9e88
dir: /bin/contrib/urldecode.awk/
#!/usr/bin/awk -f BEGIN { hextab ["0"] = 0; hextab ["8"] = 8; hextab ["1"] = 1; hextab ["9"] = 9; hextab ["2"] = 2; hextab ["A"] = hextab ["a"] = 10 hextab ["3"] = 3; hextab ["B"] = hextab ["b"] = 11; hextab ["4"] = 4; hextab ["C"] = hextab ["c"] = 12; hextab ["5"] = 5; hextab ["D"] = hextab ["d"] = 13; hextab ["6"] = 6; hextab ["E"] = hextab ["e"] = 14; hextab ["7"] = 7; hextab ["F"] = hextab ["f"] = 15; } { decoded = "" i = 1 len = length ($0) while ( i <= len ) { c = substr ($0, i, 1) if ( c == "%" ) { if ( i+2 <= len ) { c1 = substr ($0, i+1, 1) c2 = substr ($0, i+2, 1) if ( hextab [c1] == "" || hextab [c2] == "" ) { print "WARNING: invalid hex encoding: %" c1 c2 | "cat >&2" } else { code = 0 + hextab [c1] * 16 + hextab [c2] + 0 c = sprintf ("%c", code) i = i + 2 } } else { print "WARNING: invalid % encoding: " substr ($0, i, len - i) } } else if ( c == "+" ) { c = " " } decoded = decoded c ++i } print decoded }