ref: f72c551ee062c9dfedaa8223676a16209689453b
dir: /bin/contrib/urldecode.awk/
#!/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
}