43

How can I encode and decode percent-encoded (URL encoded) strings on the command line?

I'm looking for a solution that can do this:

$ percent-encode "ændrük"
%C3%A6ndr%C3%BCk
$ percent-decode "%C3%A6ndr%C3%BCk"
ændrük
3
  • Do you want to incorporate different encodings too? %E6ndr%FCk doesn't look like (standard) UTF8 to me. Or it's just an example?
    – arrange
    Jul 19, 2011 at 21:13
  • @arrange Thanks for catching that. Apparently I chose the bad apple among search results for online converters.
    – ændrük
    Jul 19, 2011 at 21:49
  • For file names, see: How to remove URI encoding in file names.
    – kenorb
    Feb 12, 2015 at 17:54

8 Answers 8

44

These commands do what you want (using Python 2):

python -c "import urllib, sys; print urllib.quote(sys.argv[1])" æ
python -c "import urllib, sys; print urllib.unquote(sys.argv[1])" %C3%A6

If you want to encode spaces as +, replace urllib.quote with urllib.quote_plus.

I'm guessing you will want to alias them ;-)

3
  • 1
    What is that æ character at the end of first line? Edit: answering to myself - got it, it's just a single character UTF8 to-be-encoded string for example purpose :-)
    – TMG
    Jan 8, 2018 at 10:03
  • 1
    how about python3?
    – RicardoE
    Aug 25, 2018 at 5:37
  • @RicardoE check this answer. Jan 17, 2019 at 19:03
38

shell

Try the following command line:

$ echo "%C3%A6ndr%C3%BCk" | sed 's@+@ @g;s@%@\\x@g' | xargs -0 printf "%b"
ændrük

You may define it as alias and add it to your shell rc files:

$ alias urldecode='sed "s@+@ @g;s@%@\\\\x@g" | xargs -0 printf "%b"'

Then every time when you need it, simply go with:

$ echo "http%3A%2F%2Fwww" | urldecode
http://www

bash

When scripting, you can use the following syntax:

input="http%3A%2F%2Fwww"
decoded=$(printf '%b' "${input//%/\\x}")

However above syntax won't handle pluses (+) correctly, so you've to replace them with spaces via sed.

You can also use the following urlencode() and urldecode() functions:

urlencode() {
    # urlencode <string>
    local length="${#1}"
    for (( i = 0; i < length; i++ )); do
        local c="${1:i:1}"
        case $c in
            [a-zA-Z0-9.~_-]) printf "$c" ;;
            *) printf '%%%02X' "'$c"
        esac
    done
}

urldecode() {
    # urldecode <string>

    local url_encoded="${1//+/ }"
    printf '%b' "${url_encoded//%/\\x}"
}

Note that your urldecode() assumes the data contains no backslash.


bash + xxd

Bash function with xxd tool:

urlencode() {
  local length="${#1}"
  for (( i = 0; i < length; i++ )); do
    local c="${1:i:1}"
    case $c in
      [a-zA-Z0-9.~_-]) printf "$c" ;;
    *) printf "$c" | xxd -p -c1 | while read x;do printf "%%%s" "$x";done
  esac
done
}

Found in cdown's gist file, also at stackoverflow.


Python

Try to define the following aliases:

alias urldecode='python -c "import sys, urllib as ul; print ul.unquote_plus(sys.argv[1])"'
alias urlencode='python -c "import sys, urllib as ul; print ul.quote_plus(sys.argv[1])"'

Usage:

$ urlencode "ændrük"
C%26ndrC%3Ck
$ urldecode "%C3%A6ndr%C3%BCk"
ændrük

Source: ruslanspivak


PHP

Using PHP you can try the following command:

$ echo oil+and+gas | php -r 'echo urldecode(fgets(STDIN));' // Or: php://stdin
oil and gas

or just:

php -r 'echo urldecode("oil+and+gas");'

Use -R for multiple line input.


Perl

In Perl you can use URI::Escape.

decoded_url=$(perl -MURI::Escape -e 'print uri_unescape($ARGV[0])' "$encoded_url")

Or to process a file:

perl -i -MURI::Escape -e 'print uri_unescape($ARGV[0])' file

sed

Using sed can be achieved by:

cat file | sed -e's/%\([0-9A-F][0-9A-F]\)/\\\\\x\1/g' | xargs echo -e

awk

Try anon solution:

awk -niord '{printf RT?$0chr("0x"substr(RT,2)):$0}' RS=%..

See: Using awk printf to urldecode text.


decoding file names

If you need to remove url encoding from the file names, use deurlname tool from renameutils (e.g. deurlname *.*).

See also:


Related:

1
  • The bash + xxd version does not work with strings that contain a %, maybe you could replace printf "$c" with printf "%c" "$c"? A other problem is that some non-ASCII charachters are not encoded (such as ä) in some language settings, maybe add a export LC_ALL=C in the function (that should not affect anything outside the function)? Oct 7, 2019 at 11:01
10

Percent-encode reserved URI characters and non-ASCII characters

jq -s -R -r @uri

-s (--slurp) reads input lines into an array and -s -R (--slurp --raw-input) reads the input into a single string. -r (--raw-output) outputs the contents of strings instead of JSON string literals.

Percent-encode all characters

xxd -p|tr -d \\n|sed 's/../%&/g'

tr -d \\n removes the linefeeds that are added by xxd -p after every 60 characters.

Percent-encode all characters except ASCII alphanumeric characters in Bash

eu () {
    local LC_ALL=C c
    while IFS= read -r -n1 -d '' c
    do 
        if [[ $c = [[:alnum:]] ]]
        then 
            printf %s "$c"
        else
            printf %%%02x "'$c"
        fi
    done
}

Without -d '' this would skip linefeeds and null bytes. Without IFS= this would replace characters in IFS with %00. Without LC_ALL=C this would for example replace with %3042 in a UTF-8 locale.

0
9

Pure bash solution for decoding only:

$ a='%C3%A6ndr%C3%BCk'
$ echo -e "${a//%/\\x}"
ændrük
7

Similar to Stefano ansqer but in Python 3:

python3 -c "import urllib.parse, sys; print(urllib.parse.quote(sys.argv[1]))" æ         # to percent-enconding
python3 -c "import urllib.parse, sys; print(urllib.parse.unquote(sys.argv[1]))" %C3%A6  # from percent-enconding

To encode also slashes:

python3 -c "import urllib.parse, sys; print(urllib.parse.quote(sys.argv[1] if len(sys.argv) > 1 else sys.stdin.read()[0:-1], \"\"))"

More info about the difference here.

1
  • For folks in 2022, that's the only version that works lol
    – rimkashox
    Dec 22, 2021 at 12:03
5

I can't comment on best answer in this thread, so here is mine.

Personally, I use these aliases for URL encoding and decoding:

alias urlencode='python -c "import urllib, sys; print urllib.quote(  sys.argv[1] if len(sys.argv) > 1 else sys.stdin.read()[0:-1])"'

alias urldecode='python -c "import urllib, sys; print urllib.unquote(sys.argv[1] if len(sys.argv) > 1 else sys.stdin.read()[0:-1])"'

Both commands allow you to convert data, passed as a command line argument or read it from standard input, because both one-liners check whether there are command line arguments (even empty ones) and process them or just read standard input otherwise.

update 2015-07-16 (empty 1st arg)

... according to @muru comment.

update 2017-05-28 (slash encoding)

If you also need to encode the slash, just add an empty second argument to the quote function, then the slash will also be encoded.

So, finally urlencode alias in bash looks like this:

alias urlencode='python -c "import urllib, sys; print urllib.quote(sys.argv[1] if len(sys.argv) > 1 else sys.stdin.read()[0:-1], \"\")"'

Example

$ urlencode "Проба пера/Pen test"
%D0%9F%D1%80%D0%BE%D0%B1%D0%B0%20%D0%BF%D0%B5%D1%80%D0%B0%2FPen%20test

$ echo "Проба пера/Pen test" | urlencode
%D0%9F%D1%80%D0%BE%D0%B1%D0%B0%20%D0%BF%D0%B5%D1%80%D0%B0%2FPen%20test

$ urldecode %D0%9F%D1%80%D0%BE%D0%B1%D0%B0%20%D0%BF%D0%B5%D1%80%D0%B0%2FPen%20test
Проба пера/Pen test

$ echo "%D0%9F%D1%80%D0%BE%D0%B1%D0%B0%20%D0%BF%D0%B5%D1%80%D0%B0%2FPen%20test" | urldecode
Проба пера/Pen test

$ urlencode "Проба пера/Pen test" | urldecode
Проба пера/Pen test

$ echo "Проба пера/Pen test" | urlencode | urldecode
Проба пера/Pen test
3
  • 1
    I think sys.argv[1] if len(sys.argv) > 1 else sys.stdin.read()[0:-1] might be more appropriate. Especially if you use this in scripts and accidentally give an empty first argument.
    – muru
    Jul 16, 2015 at 2:16
  • As per @muru comment I changed the checking for an argument on the command line. It was: len(sys.argv) < 2 and sys.stdin.read()[0:-1] or sys.argv[1] Now: sys.argv[1] if len(sys.argv) > 1 else sys.stdin.read()[0:-1] That is, if there is even an empty first argument, the command does not wait for input from the standard input, but processes an empty argument.
    – DIG mbl
    Jul 16, 2015 at 13:56
  • urldecode is printing extra new lines in output. (python3.10)
    – Akhil
    May 4, 2022 at 10:28
2

I found a package, renameutils, that contain the utility deurlname that is able to rename a file containing "percent-encoded" characters.

Unfortunately, it does not decode stdin or a command line option, but only rename a file, so you have to create a dummy file to obtain the decoding (the name of the renamed file), but with some bash scripting the process can be automated.

No information about the encoding part, even because it could be questionable which characters to encode. Only non-ASCII?

I think there should be some better tool/method.

0

Here is a POSIX Awk function for encoding:

function encodeURIComponent(str, j, q) {
  while (y++ < 125) z[sprintf("%c", y)] = y
  while (y = substr(str, ++j, 1))
    q = y ~ /[[:alnum:]_.!~*\47()-]/ ? q y : q sprintf("%%%02X", z[y])
  return q
}

Example

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