Bash URI parser using SED

Filed under: Command line tools, Networking

Warning! This version is now obsolete!
Check out the new and improved version (using only Bash built-ins) here!

Here is a command-line (bash) script that uses sed to split the segments of an URI into usable variables. It also validates the given URI since malformed strings produce the text “ERROR” which can be handled accordingly:

# Assembling a sample URI (including an injection attack)
uri_1='http://user:pass@www.example.com:19741/dir1/dir2/file.php'
uri_2='?param=some_value&array[0]=123&param2=\`cat /etc/passwd\`'
uri_3='#bottom-left'
uri="$uri_1$uri_2$uri_3"

# Parse URI
op=`echo "$uri" | sed -nrf "uri.sed"`

# Handle invalid URI
[[ $op == 'ERROR' ]] && { echo "Invalid URI!"; exit 1; }

# Execute assignments
eval "$op"

# ...work with URI components...

Notice the "uri.sed" file given to sed?
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