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

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?

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 "&".

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

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

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.

Related

Insert the contents of the variable in SED command [duplicate]

If I run these commands from a script:
#my.sh
PWD=bla
sed 's/xxx/'$PWD'/'
...
$ ./my.sh
xxx
bla
it is fine.
But, if I run:
#my.sh
sed 's/xxx/'$PWD'/'
...
$ ./my.sh
$ sed: -e expression #1, char 8: Unknown option to `s'
I read in tutorials that to substitute environment variables from shell you need to stop, and 'out quote' the $varname part so that it is not substituted directly, which is what I did, and which works only if the variable is defined immediately before.
How can I get sed to recognize a $var as an environment variable as it is defined in the shell?
Your two examples look identical, which makes problems hard to diagnose. Potential problems:
You may need double quotes, as in sed 's/xxx/'"$PWD"'/'
$PWD may contain a slash, in which case you need to find a character not contained in $PWD to use as a delimiter.
To nail both issues at once, perhaps
sed 's#xxx#'"$PWD"'#'
In addition to Norman Ramsey's answer, I'd like to add that you can double-quote the entire string (which may make the statement more readable and less error prone).
So if you want to search for 'foo' and replace it with the content of $BAR, you can enclose the sed command in double-quotes.
sed 's/foo/$BAR/g'
sed "s/foo/$BAR/g"
In the first, $BAR will not expand correctly while in the second $BAR will expand correctly.
Another easy alternative:
Since $PWD will usually contain a slash /, use | instead of / for the sed statement:
sed -e "s|xxx|$PWD|"
You can use other characters besides "/" in substitution:
sed "s#$1#$2#g" -i FILE
一. bad way: change delimiter
sed 's/xxx/'"$PWD"'/'
sed 's:xxx:'"$PWD"':'
sed 's#xxx#'"$PWD"'#'
maybe those not the final answer,
you can not known what character will occur in $PWD, / : OR #.
if delimiter char in $PWD, they will break the expression
the good way is replace(escape) the special character in $PWD.
二. good way: escape delimiter
for example:
try to replace URL as $url (has : / in content)
x.com:80/aa/bb/aa.js
in string $tmp
URL
A. use / as delimiter
escape / as \/ in var (before use in sed expression)
## step 1: try escape
echo ${url//\//\\/}
x.com:80\/aa\/bb\/aa.js #escape fine
echo ${url//\//\/}
x.com:80/aa/bb/aa.js #escape not success
echo "${url//\//\/}"
x.com:80\/aa\/bb\/aa.js #escape fine, notice `"`
## step 2: do sed
echo $tmp | sed "s/URL/${url//\//\\/}/"
URL
echo $tmp | sed "s/URL/${url//\//\/}/"
URL
OR
B. use : as delimiter (more readable than /)
escape : as \: in var (before use in sed expression)
## step 1: try escape
echo ${url//:/\:}
x.com:80/aa/bb/aa.js #escape not success
echo "${url//:/\:}"
x.com\:80/aa/bb/aa.js #escape fine, notice `"`
## step 2: do sed
echo $tmp | sed "s:URL:${url//:/\:}:g"
x.com:80/aa/bb/aa.js
With your question edit, I see your problem. Let's say the current directory is /home/yourname ... in this case, your command below:
sed 's/xxx/'$PWD'/'
will be expanded to
sed `s/xxx//home/yourname//
which is not valid. You need to put a \ character in front of each / in your $PWD if you want to do this.
Actually, the simplest thing (in GNU sed, at least) is to use a different separator for the sed substitution (s) command. So, instead of s/pattern/'$mypath'/ being expanded to s/pattern//my/path/, which will of course confuse the s command, use s!pattern!'$mypath'!, which will be expanded to s!pattern!/my/path!. I’ve used the bang (!) character (or use anything you like) which avoids the usual, but-by-no-means-your-only-choice forward slash as the separator.
Dealing with VARIABLES within sed
[root#gislab00207 ldom]# echo domainname: None > /tmp/1.txt
[root#gislab00207 ldom]# cat /tmp/1.txt
domainname: None
[root#gislab00207 ldom]# echo ${DOMAIN_NAME}
dcsw-79-98vm.us.oracle.com
[root#gislab00207 ldom]# cat /tmp/1.txt | sed -e 's/domainname: None/domainname: ${DOMAIN_NAME}/g'
--- Below is the result -- very funny.
domainname: ${DOMAIN_NAME}
--- You need to single quote your variable like this ...
[root#gislab00207 ldom]# cat /tmp/1.txt | sed -e 's/domainname: None/domainname: '${DOMAIN_NAME}'/g'
--- The right result is below
domainname: dcsw-79-98vm.us.oracle.com
VAR=8675309
echo "abcde:jhdfj$jhbsfiy/.hghi$jh:12345:dgve::" |\
sed 's/:[0-9]*:/:'$VAR':/1'
where VAR contains what you want to replace the field with
I had similar problem, I had a list and I have to build a SQL script based on template (that contained #INPUT# as element to replace):
for i in LIST
do
awk "sub(/\#INPUT\#/,\"${i}\");" template.sql >> output
done
If your replacement string may contain other sed control characters, then a two-step substitution (first escaping the replacement string) may be what you want:
PWD='/a\1&b$_' # these are problematic for sed
PWD_ESC=$(printf '%s\n' "$PWD" | sed -e 's/[\/&]/\\&/g')
echo 'xxx' | sed "s/xxx/$PWD_ESC/" # now this works as expected
for me to replace some text against the value of an environment variable in a file with sed works only with quota as the following:
sed -i 's/original_value/'"$MY_ENVIRNONMENT_VARIABLE"'/g' myfile.txt
BUT when the value of MY_ENVIRONMENT_VARIABLE contains a URL (ie https://andreas.gr) then the above was not working.
THEN use different delimiter:
sed -i "s|original_value|$MY_ENVIRNONMENT_VARIABLE|g" myfile.txt

sed doesn't catch all sets of doubles

I've writted a sed script to replace all ^^ with NULL. It seems though that sed is only catching a pair, but not including the second in that pair as it continues to search.
echo "^^^^" | sed 's/\^\^/\^NULL\^/g'
produces
^NULL^^NULL^
when it should produce
^NULL^NULL^NULL^
Try with a loop to apply your command again to modified pattern space:
echo "^^^^" | sed ':a;s/\^\^/\^NULL\^/;t a;'
To edit a file in place on OSX, try the -i flag and multiline command:
sed -i '' ':a
s/\^\^/\^NULL\^/
t a' file
With GNU sed:
sed -i ':a;s/\^\^/\^NULL\^/;t a;' file
or simply redirect the command to a temporary file before renaming it:
sed ':a;s/\^\^/\^NULL\^/;t a;' file > tmp && mv tmp file
I really like SLePort solution, but since it is not working for you, you can try with (tested on Linux, not Mac):
echo "^^^^" | sed 's/\^\^/\^NULL\^/g; s//\^NULL\^/g'
It is doing the same as the former solution, but explicitly, not looping with tags.
You can omit the pattern in the second command and sed will use the previous pattern.

Bash sed delete line from file not working

I am trying to delete a line from a text file that has a matching ID number.
Student id variable: $sid, for example 12345678;
$FILE = student_record
I first tried:
sed -i '/$sid/d' student_record.txt
Which gave me file not found. Next:
sed -i '/$sid/d' $FILE
And I get: sed: 1: "student_record": unterminated substitute in regular expression
sed -i '/12345678/d' $FILE
Same error as above
sed -i '/$sid/ d' student_record.txt
yields:
sed 1: "student_record.txt": bad flag in substitute command: 'x'
If I try without -i,
sed '/$sid/ d' $FILE
It just prints the whole file and doesn't delete any lines.
Advice would be great.
If the file is called student_record as you say for $FILE, you may be making a mistake using student_record.txt which would explain while you get file not found.
For many of the others, if you use single quotes it will not expand variables, so you'll literally be looking for the string "$sid". If you use double quotes it will expand, so try
sed -i "/$sid/d" "$FILE"
assuming you have GNU sed. If you're on something that does not have GNU, you may not have -i or it may require an argument.

sed in-place command not deleting from file in bash

I have a bash script which checks for a string pattern in file and delete entire line i same file but somehow its not deleting the line and no throwing any error .same command from command prompt deletes from file .
#array has patterns
for k in "${patternarr[#]}
do
sed -i '/$k/d' file.txt
done
sed version is >4
when this loop completes i want all lines matching string pattern in array to be deleted from file.txt
when i run sed -i '/pataern/d file.txt from command prompt then it works fine but not inside bash
Thanks in advance
Here:
sed -i '/$k/d' file.txt
The sed script is singly-quoted, which prevents shell variable expansion. It will (probably) work with
sed -i "/$k/d" file.txt
I say "probably" because what it will do depends on the contents of $k, which is just substituted into the sed code and interpreted as such. If $k contains slashes, it will break. If it comes from an untrustworthy source, you open yourself up to code injection (particularly with GNU sed, which can be made to execute shell commands).
Consider k=^/ s/^/rm -Rf \//e; #.
It is generally a bad idea to substitute shell variables into sed code (or any other code). A better way would be with GNU awk:
awk -i inplace -v pattern="$k" '!($0 ~ pattern)' file.txt
Or to just use grep -v and a temporary file.
first of all, you got an unclosed double quote around ${patternarr[#]} in your for statement.
Then your problem is that you use single quotes in the sed argument, making your shell not evaluate the $k within the quotes:
% declare -a patternarr=(foo bar fu foobar)
% for k in ${patternarr[#]}; do echo sed -i '/$k/d' file.txt; done
sed -i /$k/d file.txt
sed -i /$k/d file.txt
sed -i /$k/d file.txt
sed -i /$k/d file.txt
if you replace them with double quotes, here it goes:
% for k in ${patternarr[#]}; do echo sed -i "/$k/d" file.txt; done
sed -i /foo/d file.txt
sed -i /bar/d file.txt
sed -i /fu/d file.txt
sed -i /foobar/d file.txt
Any time you write a loop in shell just to manipulate text you have the wrong approach. This is probably closer to what you really should be doing (no surrounding loop required):
awk -v ks="${patternarr[#]}" 'BEGIN{gsub(/ /,")|(",ks); ks="("ks")} $0 !~ ks' file.txt
but there may be even better approaches still (e.g. only checking 1 field instead of the whole line, or using word boundaries, or string comparison or....) if you show us some sample input and expected output.
You need to use double quotes to interpolate shell variables inside the sed command, like:
for k in ${patternarr[#]}; do
sed -i "/$k/d" file.txt
done

using sed to find and replace in bash for loop

I have a large number of words in a text file to replace.
This script is working up until the sed command where I get:
sed: 1: "*.js": invalid command code *
PS... Bash isn't one of my strong points - this doesn't need to be pretty or efficient
cd '/Users/xxxxxx/Sites/xxxxxx'
echo `pwd`;
for line in `cat myFile.txt`
do
export IFS=":"
i=0
list=()
for word in $line; do
list[$i]=$word
i=$[i+1]
done
echo ${list[0]}
echo ${list[1]}
sed -i "s/{$list[0]}/{$list[1]}/g" *.js
done
You're running BSD sed (under OS X), therefore the -i flag requires an argument specifying what you want the suffix to be.
Also, no files match the glob *.js.
This looks like a simple typo:
sed -i "s/{$list[0]}/{$list[1]}/g" *.js
Should be:
sed -i "s/${list[0]}/${list[1]}/g" *.js
(just like the echo lines above)
So myFile.txt contains a list of from:to substitutions, and you are looping over each of those. Why don't you create a sed script from this file instead?
cd '/Users/xxxxxx/Sites/xxxxxx'
sed -e 's/^/s:/' -e 's/$/:/' myFile.txt |
# Output from first sed script is a sed script!
# It contains substitutions like this:
# s:from:to:
# s:other:substitute:
sed -f - -i~ *.js
Your sed might not like the -f - which means sed should read its script from standard input. If that is the case, perhaps you can create a temporary script like this instead;
sed -e 's/^/s:/' -e 's/$/:/' myFile.txt >script.sed
sed -f script.sed -i~ *.js
Another approach, if you don't feel very confident with sed and think you are going to forget in a week what the meaning of that voodoo symbols is, could be using IFS in a more efficient way:
IFS=":"
cat myFile.txt | while read PATTERN REPLACEMENT # You feed the while loop with stdout lines and read fields separated by ":"
do
sed -i "s/${PATTERN}/${REPLACEMENT}/g"
done
The only pitfall I can see (it may be more) is that if whether PATTERN or REPLACEMENT contain a slash (/) they are going to destroy your sed expression.
You can change the sed separator with a non-printable character and you should be safe.
Anyway, if you know whats on your myFile.txt you can just use any.

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