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How to urlencode data for curl command?

I am trying to write a bash script for testing that takes a parameter and sends it through curl to web site. I need to url encode the value to make sure that special characters are processed properly. What is the best way to do this?

Here is my basic script so far:

#!/bin/bash
host=${1:?'bad host'}
value=$2
shift
shift
curl -v -d "param=${value}" http://${host}/somepath $@

n
neu242

Use curl --data-urlencode; from man curl:

This posts data, similar to the other --data options with the exception that this performs URL-encoding. To be CGI-compliant, the part should begin with a name followed by a separator and a content specification.

Example usage:

curl \
    --data-urlencode "paramName=value" \
    --data-urlencode "secondParam=value" \
    http://example.com

See the man page for more info.

This requires curl 7.18.0 or newer (released January 2008). Use curl -V to check which version you have.

You can as well encode the query string:

curl --get \
    --data-urlencode "p1=value 1" \
    --data-urlencode "p2=value 2" \
    http://example.com
    # http://example.com?p1=value%201&p2=value%202

Seems to only work for http POST. Documentation here: curl.haxx.se/docs/manpage.html#--data-urlencode
@StanJames If you use it like so curl can also do the encoding for a GET request. curl -G --data-urlencode "blah=df ssdf sdf" --data-urlencode "blah2=dfsdf sdfsd " http://whatever.com/whatever
@kberg actually, this will only work for query data. curl will append a '?' followed by the urlencoded params. If you want to urlencode some url postfix (such as a CouchDB GET for some document id), then '--data-urlencode' won't work.
Doesn't work for curl --data-urlencode "description=![image]($url)" www.example.com. Any idea why? `
@NadavB Escaping the "
k
kthompso

Here is the pure BASH answer.

Update: Since many changes have been discussed, I have placed this on https://github.com/sfinktah/bash/blob/master/rawurlencode.inc.sh for anybody to issue a PR against.

Note: This solution is not intended to encode unicode or multi-byte characters - which are quite outside BASH's humble native capabilities. It's only intended to encode symbols that would otherwise ruin argument passing in POST or GET requests, e.g. '&', '=' and so forth.

Very Important Note: DO NOT ATTEMPT TO WRITE YOUR OWN UNICODE CONVERSION FUNCTION, IN ANY LANGUAGE, EVER. See end of answer.

rawurlencode() {
  local string="${1}"
  local strlen=${#string}
  local encoded=""
  local pos c o

  for (( pos=0 ; pos<strlen ; pos++ )); do
     c=${string:$pos:1}
     case "$c" in
        [-_.~a-zA-Z0-9] ) o="${c}" ;;
        * )               printf -v o '%%%02x' "'$c"
     esac
     encoded+="${o}"
  done
  echo "${encoded}"    # You can either set a return variable (FASTER) 
  REPLY="${encoded}"   #+or echo the result (EASIER)... or both... :p
}

You can use it in two ways:

easier:  echo http://url/q?=$( rawurlencode "$args" )
faster:  rawurlencode "$args"; echo http://url/q?${REPLY}

[edited]

Here's the matching rawurldecode() function, which - with all modesty - is awesome.

# Returns a string in which the sequences with percent (%) signs followed by
# two hex digits have been replaced with literal characters.
rawurldecode() {

  # This is perhaps a risky gambit, but since all escape characters must be
  # encoded, we can replace %NN with \xNN and pass the lot to printf -b, which
  # will decode hex for us

  printf -v REPLY '%b' "${1//%/\\x}" # You can either set a return variable (FASTER)

  echo "${REPLY}"  #+or echo the result (EASIER)... or both... :p
}

With the matching set, we can now perform some simple tests:

$ diff rawurlencode.inc.sh \
        <( rawurldecode "$( rawurlencode "$( cat rawurlencode.inc.sh )" )" ) \
        && echo Matched

Output: Matched

And if you really really feel that you need an external tool (well, it will go a lot faster, and might do binary files and such...) I found this on my OpenWRT router...

replace_value=$(echo $replace_value | sed -f /usr/lib/ddns/url_escape.sed)

Where url_escape.sed was a file that contained these rules:

# sed url escaping
s:%:%25:g
s: :%20:g
s:<:%3C:g
s:>:%3E:g
s:#:%23:g
s:{:%7B:g
s:}:%7D:g
s:|:%7C:g
s:\\:%5C:g
s:\^:%5E:g
s:~:%7E:g
s:\[:%5B:g
s:\]:%5D:g
s:`:%60:g
s:;:%3B:g
s:/:%2F:g
s:?:%3F:g
s^:^%3A^g
s:@:%40:g
s:=:%3D:g
s:&:%26:g
s:\$:%24:g
s:\!:%21:g
s:\*:%2A:g

While it is not impossible to write such a script in BASH (probably using xxd and a very lengthy ruleset) capable of handing UTF-8 input, there are faster and more reliable ways. Attempting to decode UTF-8 into UTF-32 is a non-trivial task to do with accuracy, though very easy to do inaccurately such that you think it works until the day it doesn't.

Even the Unicode Consortium removed their sample code after discovering it was no longer 100% compatible with the actual standard.

The Unicode standard is constantly evolving, and has become extremely nuanced. Any implementation you can whip together will not be properly compliant, and if by some extreme effort you managed it, it wouldn't stay compliant.


Unfortunately, this script fails on some characters, such as 'é' and '½', outputting 'e%FFFFFFFFFFFFFFCC' and '%FFFFFFFFFFFFFFC2', respectively (b/c of the per-character loop, I believe).
It fails to work for me in Bash 4.3.11(1). The string Jogging «à l'Hèze» generates Jogging%20%abà%20l%27Hèze%bb that cannot be feed to JS decodeURIComponent :(
In that first block of code what does the last parameter to printf mean? That is, why is it double-quote, single-quote, dollar-sign, letter-c, double-quote? Does does the single-quote do?
@ColinFraizer the single quote serves to convert the following character into its numeric value. ref. pubs.opengroup.org/onlinepubs/9699919799/utilities/…
@Matthematics, @dmcontador, @Orwellophile: I was wrong in my previous comment. Solution using xxd is beter and works in any case (for any character). I have updated my script. Anyway, it looks like the rawurldecode() function works exceptionally well. :)
n
nisetama

Another option is to use jq:

$ printf %s 'encode this'|jq -sRr @uri
encode%20this
$ jq -rn --arg x 'encode this' '$x|@uri'
encode%20this

-r (--raw-output) outputs the raw contents of strings instead of JSON string literals. -n (--null-input) doesn't read input from STDIN.

-R (--raw-input) treats input lines as strings instead of parsing them as JSON, and -sR (--slurp --raw-input) reads the input into a single string. You can replace -sRr with -Rr if your input only contains a single line, or if you don't want to replace linefeeds with %0A:

$ printf %s\\n 'multiple lines' 'of text'|jq -Rr @uri
multiple%20lines
of%20text
$ printf %s\\n 'multiple lines' 'of text'|jq -sRr @uri
multiple%20lines%0Aof%20text%0A

Or this percent-encodes all bytes:

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

<3 it ... should be top & accepted IMO (yeah if you can tell curl to encode that works and if bash has a builtin that would have been acceptable - but jq seems like a right fit tho i'm far from attaining comfort level with this tool)
for anyone wondering the same thing as me: @uri is not some variable, but a literal jq filter used for formatting strings and escaping; see jq manual for details (sorry, no direct link, need to search for @uri on the page...)
the xxd version is just the kind of thing I was looking for. Even if it's a little dirty, it's short and has no dependencies
A sample usage of jq to url-encode: printf "http://localhost:8082/" | jq -sRr '@uri'
I think the only reason this isn't the top answer is because OP specifically asked about curl. You wouldn't loop in a second tool, jq, if curl can do it alone. However, this is awesome general utility to pipe output to, in a script or on the command line.
d
dubek

Use Perl's URI::Escape module and uri_escape function in the second line of your bash script:

...

value="$(perl -MURI::Escape -e 'print uri_escape($ARGV[0]);' "$2")"
...

Edit: Fix quoting problems, as suggested by Chris Johnsen in the comments. Thanks!


URI::Escape might not be installed, check my answer in that case.
I fixed this (use echo, pipe and <>), and now it works even when $2 contains an apostrophe or double-quotes. Thanks!
You do away with echo, too: value="$(perl -MURI::Escape -e 'print uri_escape($ARGV[0]);' "$2")"
Chris Johnsen's version is better. I had ${True} in my test expression and using this via echo tripped up uri_escape / Perl variable expansion.
@jrw32982 yeah, looking back at it, having another language with which to accomplish this task is good. If I could, I'd take back my downvote, but alas it is currently locked in.
B
Bruno Bronosky

One of variants, may be ugly, but simple:

urlencode() {
    local data
    if [[ $# != 1 ]]; then
        echo "Usage: $0 string-to-urlencode"
        return 1
    fi
    data="$(curl -s -o /dev/null -w %{url_effective} --get --data-urlencode "$1" "")"
    if [[ $? != 3 ]]; then
        echo "Unexpected error" 1>&2
        return 2
    fi
    echo "${data##/?}"
    return 0
}

Here is the one-liner version for example (as suggested by Bruno):

date | curl -Gso /dev/null -w %{url_effective} --data-urlencode @- "" | cut -c 3-

# If you experience the trailing %0A, use
date | curl -Gso /dev/null -w %{url_effective} --data-urlencode @- "" | sed -E 's/..(.*).../\1/'

I think this is a very clever way to reuse cURL's URL encoding.
This is absolutely brilliant! I really wish you had left it a one line so that people can see how simple it really is. To URL encode the result of the date command… date | curl -Gso /dev/null -w %{url_effective} --data-urlencode @- "" | cut -c 3- (You have to cut the first 2 chars off, because curl's output is a technically a relative URL with a query string.)
@BrunoBronosky Your one-liner variant is good but seemingly adds a "%0A" to the end of the encoding. Users beware. The function version does not seem to have this issue.
To avoid %0A at the end, use printf instead of echo.
the one liner is fantastic
j
josch

for the sake of completeness, many solutions using sed or awk only translate a special set of characters and are hence quite large by code size and also dont translate other special characters that should be encoded.

a safe way to urlencode would be to just encode every single byte - even those that would've been allowed.

echo -ne 'some random\nbytes' | xxd -plain | tr -d '\n' | sed 's/\(..\)/%\1/g'

xxd is taking care here that the input is handled as bytes and not characters.

edit:

xxd comes with the vim-common package in Debian and I was just on a system where it was not installed and I didnt want to install it. The altornative is to use hexdump from the bsdmainutils package in Debian. According to the following graph, bsdmainutils and vim-common should have an about equal likelihood to be installed:

http://qa.debian.org/popcon-png.php?packages=vim-common%2Cbsdmainutils&show_installed=1&want_legend=1&want_ticks=1

but nevertheless here a version which uses hexdump instead of xxd and allows to avoid the tr call:

echo -ne 'some random\nbytes' | hexdump -v -e '/1 "%02x"' | sed 's/\(..\)/%\1/g'

xxd -plain should happen AFTER tr -d '\n' !
@qdii why? that would not only make it impossible to urlencode newlines but it would also wrongly insert newlines created by xxd into the output.
@josch. This is just plain wrong. First, any \n characters will be translated by xxd -plain into 0a. Don’t take my word for it, try it yourself: echo -n -e '\n' | xxd -plain This proves that your tr -d '\n' is useless here as there cannot be any \n after xxd -plain Second, echo foobar adds its own \n character in the end of the character string, so xxd -plain is not fed with foobar as expected but with foobar\n. then xxd -plain translates it into some character string that ends in 0a, making it unsuitable for the user. You could add -n to echo to solve it.
@qdii indeed -n was missing for echo but the xxd call belongs in front of the tr -d call. It belongs there so that any newline in foobar is translated by xxd. The tr -d after the xxd call is to remove the newlines that xxd produces. It seems you never have foobar long enough so that xxd produces newlines but for long inputs it will. So the tr -d is necessary. In contrast to your assumption the tr -d was NOT to remove newlines from the input but from the xxd output. I want to keep the newlines in the input. Your only valid point is, that echo adds an unnecessary newline.
@qdii and no offence taken - I just think that you are wrong, except for the echo -n which I was indeed missing
k
kynan

I find it more readable in python:

encoded_value=$(python3 -c "import urllib.parse; print urllib.parse.quote('''$value''')")

the triple ' ensures that single quotes in value won't hurt. urllib is in the standard library. It work for example for this crazy (real world) url:

"http://www.rai.it/dl/audio/" "1264165523944Ho servito il re d'Inghilterra - Puntata 7

I had some trouble with quotes and special chars with the triplequoting, this seemed to work for basically everything: encoded_value="$( echo -n "${data}" | python -c "import urllib; import sys; sys.stdout.write(urllib.quote(sys.stdin.read()))" )";
Python 3 version would be encoded_value=$(python3 -c "import urllib.parse; print (urllib.parse.quote('''$value'''))").
The urllib.parse.quote does not encode forward slashes '/'. urlencode() { python3 -c 'import urllib.parse; import sys; print(urllib.parse.quote(sys.argv[1], safe=""))' "$1" }
It would be much safer to refer to sys.argv rather than substituting $value into a string later parsed as code. What if value contained ''' + __import__("os").system("rm -rf ~") + '''?
python -c "import urllib;print urllib.quote(raw_input())" <<< "$data"
M
MDMower

I've found the following snippet useful to stick it into a chain of program calls, where URI::Escape might not be installed:

perl -p -e 's/([^A-Za-z0-9])/sprintf("%%%02X", ord($1))/seg'

(source)


worked for me. I changed it to perl -lpe ... (the letter ell). This removed the trailing newline, which I needed for my purposes.
FYI, to do the inverse of this, use perl -pe 's/\%(\w\w)/chr hex $1/ge' (source: unix.stackexchange.com/questions/159253/…)
Depending on specifically which characters you need to encode, you can simplify this to perl -pe 's/(\W)/sprintf("%%%02X", ord($1))/ge' which allows letters, numbers, and underscores, but encodes everything else.
Thanks for response above! Since the use case is for curl: That is: : and / does not need encoding, my final function in my bashrc/zshrc is: perl -lpe 's/([^A-Za-z0-9.\/:])/sprintf("%%%02X", ord($1))/seg
@TobiasFeil it comes from stdin.
P
Piotr Czapla

If you wish to run GET request and use pure curl just add --get to @Jacob's solution.

Here is an example:

curl -v --get --data-urlencode "access_token=$(cat .fb_access_token)" https://graph.facebook.com/me/feed

c
chenzhiwei

This may be the best one:

after=$(echo -e "$before" | od -An -tx1 | tr ' ' % | xargs printf "%s")

This works for me with two additions: 1. replace the -e with -n to avoid adding a newline to the end of the argument and 2. add '%%' to the printf string to put a % in front of each pair of hex digits.
works after add $ ahead bracket after=$(echo -e ...
Please explain how this works. The od command is not common.
This does not work with OS X's od because it uses a different output format than GNU od. For example printf aa|od -An -tx1 -v|tr \ - prints -----------61--61-------------------------------------------------------- with OS X's od and -61-61 with GNU od. You could use od -An -tx1 -v|sed 's/ */ /g;s/ *$//'|tr \ %|tr -d \\n with either OS X's od or GNU od. xxd -p|sed 's/../%&/g'|tr -d \\n does the same thing, even though xxd is not in POSIX but od is.
Although this might work, it escapes every single character
P
Pokechu22

Direct link to awk version : http://www.shelldorado.com/scripts/cmds/urlencode
I used it for years and it works like a charm

:
##########################################################################
# Title      :  urlencode - encode URL data
# Author     :  Heiner Steven (heiner.steven@odn.de)
# Date       :  2000-03-15
# Requires   :  awk
# Categories :  File Conversion, WWW, CGI
# SCCS-Id.   :  @(#) urlencode  1.4 06/10/29
##########################################################################
# Description
#   Encode data according to
#       RFC 1738: "Uniform Resource Locators (URL)" and
#       RFC 1866: "Hypertext Markup Language - 2.0" (HTML)
#
#   This encoding is used i.e. for the MIME type
#   "application/x-www-form-urlencoded"
#
# Notes
#    o  The default behaviour is not to encode the line endings. This
#   may not be what was intended, because the result will be
#   multiple lines of output (which cannot be used in an URL or a
#   HTTP "POST" request). If the desired output should be one
#   line, use the "-l" option.
#
#    o  The "-l" option assumes, that the end-of-line is denoted by
#   the character LF (ASCII 10). This is not true for Windows or
#   Mac systems, where the end of a line is denoted by the two
#   characters CR LF (ASCII 13 10).
#   We use this for symmetry; data processed in the following way:
#       cat | urlencode -l | urldecode -l
#   should (and will) result in the original data
#
#    o  Large lines (or binary files) will break many AWK
#       implementations. If you get the message
#       awk: record `...' too long
#        record number xxx
#   consider using GNU AWK (gawk).
#
#    o  urlencode will always terminate it's output with an EOL
#       character
#
# Thanks to Stefan Brozinski for pointing out a bug related to non-standard
# locales.
#
# See also
#   urldecode
##########################################################################

PN=`basename "$0"`          # Program name
VER='1.4'

: ${AWK=awk}

Usage () {
    echo >&2 "$PN - encode URL data, $VER
usage: $PN [-l] [file ...]
    -l:  encode line endings (result will be one line of output)

The default is to encode each input line on its own."
    exit 1
}

Msg () {
    for MsgLine
    do echo "$PN: $MsgLine" >&2
    done
}

Fatal () { Msg "$@"; exit 1; }

set -- `getopt hl "$@" 2>/dev/null` || Usage
[ $# -lt 1 ] && Usage           # "getopt" detected an error

EncodeEOL=no
while [ $# -gt 0 ]
do
    case "$1" in
        -l) EncodeEOL=yes;;
    --) shift; break;;
    -h) Usage;;
    -*) Usage;;
    *)  break;;         # First file name
    esac
    shift
done

LANG=C  export LANG
$AWK '
    BEGIN {
    # We assume an awk implementation that is just plain dumb.
    # We will convert an character to its ASCII value with the
    # table ord[], and produce two-digit hexadecimal output
    # without the printf("%02X") feature.

    EOL = "%0A"     # "end of line" string (encoded)
    split ("1 2 3 4 5 6 7 8 9 A B C D E F", hextab, " ")
    hextab [0] = 0
    for ( i=1; i<=255; ++i ) ord [ sprintf ("%c", i) "" ] = i + 0
    if ("'"$EncodeEOL"'" == "yes") EncodeEOL = 1; else EncodeEOL = 0
    }
    {
    encoded = ""
    for ( i=1; i<=length ($0); ++i ) {
        c = substr ($0, i, 1)
        if ( c ~ /[a-zA-Z0-9.-]/ ) {
        encoded = encoded c     # safe character
        } else if ( c == " " ) {
        encoded = encoded "+"   # special handling
        } else {
        # unsafe character, encode it as a two-digit hex-number
        lo = ord [c] % 16
        hi = int (ord [c] / 16);
        encoded = encoded "%" hextab [hi] hextab [lo]
        }
    }
    if ( EncodeEOL ) {
        printf ("%s", encoded EOL)
    } else {
        print encoded
    }
    }
    END {
        #if ( EncodeEOL ) print ""
    }
' "$@"

Is there a simple variation to get UTF-8 encoding instead of ASCII?
d
davidchambers

Here's a Bash solution which doesn't invoke any external programs:

uriencode() {
  s="${1//'%'/%25}"
  s="${s//' '/%20}"
  s="${s//'"'/%22}"
  s="${s//'#'/%23}"
  s="${s//'$'/%24}"
  s="${s//'&'/%26}"
  s="${s//'+'/%2B}"
  s="${s//','/%2C}"
  s="${s//'/'/%2F}"
  s="${s//':'/%3A}"
  s="${s//';'/%3B}"
  s="${s//'='/%3D}"
  s="${s//'?'/%3F}"
  s="${s//'@'/%40}"
  s="${s//'['/%5B}"
  s="${s//']'/%5D}"
  printf %s "$s"
}

This behaves differently between the bash versions. On RHEL 6.9 the bash is 4.1.2 and it includes the single quotes. While Debian 9 and bash 4.4.12 is fine with the single quotes. For me removing the single quotes made it work on both. s="${s//','/%2C}"
I updated the answer to reflect your finding, @muni764.
Just a warning... this won't encode things like the character á
C
Cody Gray
url=$(echo "$1" | sed -e 's/%/%25/g' -e 's/ /%20/g' -e 's/!/%21/g' -e 's/"/%22/g' -e 's/#/%23/g' -e 's/\$/%24/g' -e 's/\&/%26/g' -e 's/'\''/%27/g' -e 's/(/%28/g' -e 's/)/%29/g' -e 's/\*/%2a/g' -e 's/+/%2b/g' -e 's/,/%2c/g' -e 's/-/%2d/g' -e 's/\./%2e/g' -e 's/\//%2f/g' -e 's/:/%3a/g' -e 's/;/%3b/g' -e 's//%3e/g' -e 's/?/%3f/g' -e 's/@/%40/g' -e 's/\[/%5b/g' -e 's/\\/%5c/g' -e 's/\]/%5d/g' -e 's/\^/%5e/g' -e 's/_/%5f/g' -e 's/`/%60/g' -e 's/{/%7b/g' -e 's/|/%7c/g' -e 's/}/%7d/g' -e 's/~/%7e/g')

this will encode the string inside of $1 and output it in $url. although you don't have to put it in a var if you want. BTW didn't include the sed for tab thought it would turn it into spaces


I get the feeling this is not the recommended way to do this.
explain your feeling please.... because I what I have stated works and I have used it in several scripts so I know it works for all the chars I listed. so please explain why someone would not use my code and use perl since the title of this is "URLEncode from a bash script" not a perl script.
sometimes no pearl solution is needed so this can come in handy
This is not the recommended way to do this because blacklist is bad practice, and this is unicode unfriendly anyway.
This was the most friendly solution compatible with cat file.txt
D
Darren Weber

Using php from a shell script:

value="http://www.google.com"
encoded=$(php -r "echo rawurlencode('$value');")
# encoded = "http%3A%2F%2Fwww.google.com"
echo $(php -r "echo rawurldecode('$encoded');")
# returns: "http://www.google.com"

http://www.php.net/manual/en/function.rawurlencode.php http://www.php.net/manual/en/function.rawurldecode.php


t
thecoshman

If you don't want to depend on Perl you can also use sed. It's a bit messy, as each character has to be escaped individually. Make a file with the following contents and call it urlencode.sed

s/%/%25/g
s/ /%20/g
s/ /%09/g
s/!/%21/g
s/"/%22/g
s/#/%23/g
s/\$/%24/g
s/\&/%26/g
s/'\''/%27/g
s/(/%28/g
s/)/%29/g
s/\*/%2a/g
s/+/%2b/g
s/,/%2c/g
s/-/%2d/g
s/\./%2e/g
s/\//%2f/g
s/:/%3a/g
s/;/%3b/g
s//%3e/g
s/?/%3f/g
s/@/%40/g
s/\[/%5b/g
s/\\/%5c/g
s/\]/%5d/g
s/\^/%5e/g
s/_/%5f/g
s/`/%60/g
s/{/%7b/g
s/|/%7c/g
s/}/%7d/g
s/~/%7e/g
s/      /%09/g

To use it do the following.

STR1=$(echo "https://www.example.com/change&$ ^this to?%checkthe@-functionality" | cut -d\? -f1)
STR2=$(echo "https://www.example.com/change&$ ^this to?%checkthe@-functionality" | cut -d\? -f2)
OUT2=$(echo "$STR2" | sed -f urlencode.sed)
echo "$STR1?$OUT2"

This will split the string into a part that needs encoding, and the part that is fine, encode the part that needs it, then stitches back together.

You can put that into a sh script for convenience, maybe have it take a parameter to encode, put it on your path and then you can just call:

urlencode https://www.exxample.com?isThisFun=HellNo

source


W
Wolfgang Fahl

Python 3 based on @sandro's good answer from 2010:

echo "Test & /me" | python -c "import urllib.parse;print (urllib.parse.quote(input()))"

Test%20%26%20/me


a
ataylor

For those of you looking for a solution that doesn't need perl, here is one that only needs hexdump and awk:

url_encode() {
 [ $# -lt 1 ] && { return; }

 encodedurl="$1";

 # make sure hexdump exists, if not, just give back the url
 [ ! -x "/usr/bin/hexdump" ] && { return; }

 encodedurl=`
   echo $encodedurl | hexdump -v -e '1/1 "%02x\t"' -e '1/1 "%_c\n"' |
   LANG=C awk '
     $1 == "20"                    { printf("%s",   "+"); next } # space becomes plus
     $1 ~  /0[adAD]/               {                      next } # strip newlines
     $2 ~  /^[a-zA-Z0-9.*()\/-]$/  { printf("%s",   $2);  next } # pass through what we can
                                   { printf("%%%s", $1)        } # take hex value of everything else
   '`
}

Stitched together from a couple of places across the net and some local trial and error. It works great!


k
kev

uni2ascii is very handy:

$ echo -ne '你好世界' | uni2ascii -aJ
%E4%BD%A0%E5%A5%BD%E4%B8%96%E7%95%8C

This doesn't work for characters inside the ASCII range, that need quoting, like % and space (that last can be remedied with the -s flag)
K
Klaus

You can emulate javascript's encodeURIComponent in perl. Here's the command:

perl -pe 's/([^a-zA-Z0-9_.!~*()'\''-])/sprintf("%%%02X", ord($1))/ge'

You could set this as a bash alias in .bash_profile:

alias encodeURIComponent='perl -pe '\''s/([^a-zA-Z0-9_.!~*()'\''\'\'''\''-])/sprintf("%%%02X",ord($1))/ge'\'

Now you can pipe into encodeURIComponent:

$ echo -n 'hèllo wôrld!' | encodeURIComponent
h%C3%A8llo%20w%C3%B4rld!

M
Marcus Müller

Simple PHP option:

echo 'part-that-needs-encoding' | php -R 'echo urlencode($argn);'

m
masterxilo

This nodejs-based answer will use encodeURIComponent on stdin:

uriencode_stdin() {
    node -p 'encodeURIComponent(require("fs").readFileSync(0))'
}

echo -n $'hello\nwörld' | uriencode_stdin
hello%0Aw%C3%B6rld


Best version out there ;)
N
Nestor Urquiza

What would parse URLs better than javascript?

node -p "encodeURIComponent('$url')"

Out of op question scope. Not bash, not curl. Even if I'm sure works very good if node is available.
Why down-voting this and not the python/perl answers? Furthermore how this does not respond the original question "How to urlencode data for curl command?". This can be used from a bash script and the result can be given to a curl command.
I down-voted the others too. The question was how to do this in a bash script. If another language is used like node/js, python or perl, there is no need to use curl directly then.
While I didn't bother to downvote, the problem with this command is that it requires data to be properly escaped for use in javascript. Like try it with single quotes and some backslash madness. If you want to use node, you better read stuff from stdin like node -p 'encodeURIComponent(require("fs").readFileSync(0))'
Be careful with @MichaelKrelin-hacker's solution if you are piping data in from STDIN make sure not to include a trailing newline. For example, echo | ... is wrong, while echo -n | ... suppresses the newline.
d
davidchambers

Here's the node version:

uriencode() {
  node -p "encodeURIComponent('${1//\'/\\\'}')"
}

Won't this break if there are any other characters in the string that aren't valid between single quotes, like a single backslash, or newlines?
Good point. If we're to go to the trouble of escaping all the problematic characters in Bash we might as well perform the replacements directly and avoid node altogether. I posted a Bash-only solution. :)
This variant found elsewhere on the page avoids the quoting issue by reading the value from STDIN: node -p 'encodeURIComponent(require("fs").readFileSync(0))'
D
Dylan

The question is about doing this in bash and there's no need for python or perl as there is in fact a single command that does exactly what you want - "urlencode".

value=$(urlencode "${2}")

This is also much better, as the above perl answer, for example, doesn't encode all characters correctly. Try it with the long dash you get from Word and you get the wrong encoding.

Note, you need "gridsite-clients" installed to provide this command.


My version of bash (GNU 3.2) doesn't have urlencode. What version are you using?
I have 4.3.42, but the urlencode command is provided by "gridsite-clients". Try installing that and you should be fine.
So your answer is not better than any that require others things installed (python, perl, lua, …)
Except that it only requires installing a single utility instead of an entire language (and libraries), plus is super simple and clear to see what it's doing.
A link first for the package / project page providing this command would have been useful.
j
jan halfar

Another php approach:

echo "encode me" | php -r "echo urlencode(file_get_contents('php://stdin'));"

echo will append a newline character (hex 0xa). To stop it doing that, use echo -n.
Z
Zombo

Here is a POSIX function to do that:

url_encode() {
   awk 'BEGIN {
      for (n = 0; n < 125; n++) {
         m[sprintf("%c", n)] = n
      }
      n = 1
      while (1) {
         s = substr(ARGV[1], n, 1)
         if (s == "") {
            break
         }
         t = s ~ /[[:alnum:]_.!~*\47()-]/ ? t s : t sprintf("%%%02X", m[s])
         n++
      }
      print t
   }' "$1"
}

Example:

value=$(url_encode "$2")

k
k107

Ruby, for completeness

value="$(ruby -r cgi -e 'puts CGI.escape(ARGV[0])' "$2")"

n
nulleight

Here is my version for busybox ash shell for an embedded system, I originally adopted Orwellophile's variant:

urlencode()
{
    local S="${1}"
    local encoded=""
    local ch
    local o
    for i in $(seq 0 $((${#S} - 1)) )
    do
        ch=${S:$i:1}
        case "${ch}" in
            [-_.~a-zA-Z0-9]) 
                o="${ch}"
                ;;
            *) 
                o=$(printf '%%%02x' "'$ch")                
                ;;
        esac
        encoded="${encoded}${o}"
    done
    echo ${encoded}
}

urldecode() 
{
    # urldecode <string>
    local url_encoded="${1//+/ }"
    printf '%b' "${url_encoded//%/\\x}"
}

C
Community

Here's a one-line conversion using Lua, similar to blueyed's answer except with all the RFC 3986 Unreserved Characters left unencoded (like this answer):

url=$(echo 'print((arg[1]:gsub("([^%w%-%.%_%~])",function(c)return("%%%02X"):format(c:byte())end)))' | lua - "$1")

Additionally, you may need to ensure that newlines in your string are converted from LF to CRLF, in which case you can insert a gsub("\r?\n", "\r\n") in the chain before the percent-encoding.

Here's a variant that, in the non-standard style of application/x-www-form-urlencoded, does that newline normalization, as well as encoding spaces as '+' instead of '%20' (which could probably be added to the Perl snippet using a similar technique).

url=$(echo 'print((arg[1]:gsub("\r?\n", "\r\n"):gsub("([^%w%-%.%_%~ ]))",function(c)return("%%%02X"):format(c:byte())end):gsub(" ","+"))' | lua - "$1")

a
ajaest

Having php installed I use this way:

URL_ENCODED_DATA=`php -r "echo urlencode('$DATA');"`

that might not handle $DATA when it contains single quote ' characters?