CODEWITHSUNDEEP
bashvariablesunixsedescaping
gotgameg
gotgameg

Reputation: 43

Sed - replacing a string with a variable full of weird characters

I'm using sed to replace a character in a file with a variable. This variable is basically reading the contents of a file or a webpage which contains multiple hash-like strings like below, which are randomly generated:

define('AUTH_KEY',         'CVo|BO;Qt1B|+GE}+h2/yU7h=5`/wRV{>%h.b_;s%S8-p|>qpf]|/Vf@`&[g~*:&');
define('SECURE_AUTH_KEY',  '{G2-<^jWRd7]2,?]6hhM^*asg.2C.+k=gf33-m+ZK_{Mt|q*<ELF4|gPjyxtTh!)');
define('LOGGED_IN_KEY',    'jSNo9Z;5d]tzZoh-QQ`{M-&~y??$R({:*m`0={67=+mF?L.e+R{;)+4}qCAAHz=C');
define('NONCE_KEY',        '19Vt4=%8j/Z-&~ni0S<]9)J^~sy9dh|h9M_RX2#K0]F9+.v+[BP1d&B&}-FTKIJ,');
define('AUTH_SALT',        'jr7f?T|@Cbo]XVAo}N^ilkvD>dC-rr]5{al64|?_Hz }JG$yEi:_aU )Olp YAD+');
define('SECURE_AUTH_SALT', 'hm#Z%O!X_mr?lM|>>~r-?F%wi R($}|9R[):4^NTsj+gS[qnv}7|+0<9e-$DJjju');
define('LOGGED_IN_SALT',   'tyPHBOCkXZh_4H;G|^.&|^#JPB/f;{}y_Orj!6AH?@wovx+KKtTZ A[HMS9SZJ|N');
define('NONCE_SALT',       'Eb-/t 5D-vPV9I--8F<[^lcherGv.g+|7p6;+xP|5g6P}tup1K.vuHAQ=uWZ#}H^');

The variable is defined like so:

KEY=$(cat keyfile)

I used the following sed syntax:

sed -i "s/stringtoreplace/$KEY/" /path/to/file

I've also tried different variations, using single-quotes, quotes around the variables

sed -i "s/stringtoreplace/"$KEY"/" /path/to/file

sed -i "s/stringtoreplace/"${KEY}"/" /path/to/file

sed -i "s/stringtoreplace/'$KEY'/" /path/to/file

I think I "brute-forced" every way possible to put quotes and I don't know how to escape randomly generated characters like those. I keep getting the following error:

unterminated s command

Any suggestions on how to replace the string with the weird-hash-like variable?

Upvotes: 2

Views: 1185

Answers (4)

Ed Morton
Ed Morton

Reputation: 203607

sed is an excellent tool for simple substitutions on a single line but for anything else you should use awk:

awk -v key="$KEY" '{sub(/stringtoreplace/,key)}1' file

That will work no matter what characters "$KEY" contains, except for "&".

Upvotes: 3

rici
rici

Reputation: 241731

One possibility is to use bash instead of sed. That makes the substitution easy, but you'll have to emulate the -i option.

Something like this:

TMPFILE=$(mktemp)
KEY=$(cat keyfile)
while IFS= read -r LINE; do
  echo "${LINE//stringtoreplace/$KEY}"
done </path/to/file >$TMPFILE
mv $TMPFILE /path/to/file

Upvotes: 1

glenn jackman
glenn jackman

Reputation: 246827

The problem is that the $KEY variable contains slashes, which are the delimiters for your s command.

sed can do more than search and replace:

sed '/stringtoreplace/{
     d
     r keyfile
}' /path/to/file

I'm assuming "stringtoreplace" occurs by itself on a line.

Upvotes: 0

Nehal J Wani
Nehal J Wani

Reputation: 16619

Try this:

KEY=$(cat keyfile | sed -e 's/[]\/()$*.^|[]/\\&/g')
sed -i "s/stringtoreplace/$KEY/" /path/to/file

Upvotes: 0

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