urldecoding with one pure BASH builtin

VAR="%23%21%2fbin%2fbash" ; printf -v VAR "%b" "${VAR//\%/\x}" ; echo $VAR
You can use ordinary printf to convert "%23%21%2fbin%2fbash" into "#!/bin/bash" with no external utilities, by using a little known printf feature -- the "%b" specifier converts shell escapes. Replace % with \x and printf will understand the urlencoded string. BASH's printf has an extension to set a variable directly, too. So you get to convert urlencoded strings from garble to plaintext in one step with no externals and no backticks.
Sample Output
#!/bin/bash

6
By: Corona688
2012-01-06 22:09:01

6 Alternatives + Submit Alt

What Others Think

is there a way to encode with printf too ?
glaudiston · 296 weeks and 2 days ago
not in one line cat file | sed -e's/%\([0-9A-F][0-9A-F]\)/\\\\\x\1/g' | xargs -L 1 echo -e
qwer · 287 weeks and 2 days ago
Use of only shell builtins has to win points over pipes and writing one line perl programs, slick fix Corona
teknopaul · 281 weeks and 5 days ago

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Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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