下面是一个POSIX函数:

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"
}

例子:

value=$(url_encode "$2")

awk版本的直接链接:http://www.shelldorado.com/scripts/cmds/urlencode 我用了很多年了，效果很好

:
##########################################################################
# 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 ($0, i, 1)
        if ( c ~ /[a-zA-Z0-9.-]/ ) {
        encoded = encoded c     # safe character
        } else if ( c == " " ) {
        encoded = encoded "+"   # special handling
        } else {
        # unsafe character, encode it as a two-digit hex-number
        lo = ord [c] % 16
        hi = int (ord [c] / 16);
        encoded = encoded "%" hextab [hi] hextab [lo]
        }
    }
    if ( EncodeEOL ) {
        printf ("%s", encoded EOL)
    } else {
        print encoded
    }
    }
    END {
        #if ( EncodeEOL ) print ""
    }
' "$@"

下面是一个POSIX函数:

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"
}

例子:

value=$(url_encode "$2")

这是orwellophile回答的ksh版本，包含rawurlencode和rawurldecode函数(链接:如何为curl命令urlencode数据?)我没有足够的代表发表评论，因此有了新的帖子。

#!/bin/ksh93

function rawurlencode
{
    typeset string="${1}"
    typeset strlen=${#string}
    typeset encoded=""

    for (( pos=0 ; pos<strlen ; pos++ )); do
        c=${string:$pos:1}
        case "$c" in
            [-_.~a-zA-Z0-9] ) o="${c}" ;;
            * )               o=$(printf '%%%02x' "'$c")
        esac
        encoded+="${o}"
    done
    print "${encoded}"
}

function rawurldecode
{
    printf $(printf '%b' "${1//%/\\x}")
}

print $(rawurlencode "C++")     # --> C%2b%2b
print $(rawurldecode "C%2b%2b") # --> C++

对于我的一个案例，我发现NodeJS url库有最简单的解决方案。当然是YMMV

$ urlencode(){ node -e "console.log(require('url').parse(process.argv.slice(1).join('+')).href)" "$@"; }

$ urlencode "https://example.com?my_database_has=these 'nasty' query strings in it"
https://example.com/?my_database_has=these%20%27nasty%27%20query%20strings%20in%20it

从shell脚本中使用php:

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