I have a string like below
abc="where session = '001122' and indicator = 'X'"
I want to convert it to
eng="where session in ('001122') and indicator in ('X')"
I have tried like below using sed in bash
eng=$(echo $abc | sed -r "s/=\s+('[^']+')/in (\1)/g")
I am still get the input itself. What am I doing wrong.
You can use unadorned sed with escaped to escape the capture group parentheses (\( and \)), as well as one-or-more quantifiers (\+):
$ eng=$(echo "$abc" | sed "s/=\s\+'\([^']\+\)'/in ('\1')/g"
$ echo "$eng"
where session in ('001122') and indicator in ('X')
It is also probably a good idea to quote your expansion of abc, since it has spaces in it, but not strictly necessary in this context.
Your original code may not have worked because -r is a GNU extension. The synonym -E used to be as well, but is now part of the POSIX standard, and should therefore be relatively portable. The following version should therefore have no problems either:
$ eng=$(echo "$abc" | sed -E "s/=\s+'([^']+)'/in ('\1')/g"
Related
Using sed I want to parse Heroku's log-runtime-metrics like this one:
2016-01-29T00:38:43.662697+00:00 heroku[worker.2]: source=worker.2 dyno=heroku.17664470.d3f28df1-e15f-3452-1234-5fd0e244d46f sample#memory_total=54.01MB sample#memory_rss=54.01MB sample#memory_cache=0.00MB sample#memory_swap=0.00MB sample#memory_pgpgin=17492pages sample#memory_pgpgout=3666pages
the desired output is:
worker.2: 54.01MB (54.01MB is being memory_total)
I could not manage although I tried several alternatives including:
sed -E 's/.+source=(.+) .+memory_total=(.+) .+/\1: \2/g'
What is wrong with my command? How can it be corrected?
The .+ after source= and memory_total= are both greedy, so they accept as much of the line as possible. Use [^ ] to mean "anything except a space" so that it knows where to stop.
sed -E 's/.+source=([^ ]+) .+memory_total=([^ ]+) .+/\1: \2/g'
Putting your content into https://regex101.com/ makes it really obvious what's going on.
I'd go for the old-fashioned, reliable, non-extended sed expressions and make sure that the patterns are not too greedy:
sed -e 's/.*source=\([^ ]*\) .*memory_total=\([^ ]*\) .*/\1: \2/'
The -e is not the opposite of -E, which is primarily a Mac OS X (BSD) sed option; the normal option for GNU sed is -r instead. The -e simply means that the next argument is an expression in the script.
This produces your desired output from the given line of data:
worker.2: 54.01MB
Bonus question: There are some odd lines within the stream, I can usually filter them out using a grep pipe like | grep memory_total. However if I try to use it along with the sed command, it does not work. No output is produced with this:
heroku logs -t -s heroku | grep memory_total | sed.......
Sometimes grep | sed is necessary, but it is often redundant (unless you are using a grep feature that isn't readily supported by sed, such as Perl regular expressions).
You should be able to use:
sed -n -e '/memory_total=/ s/.*source=\([^ ]*\) .*memory_total=\([^ ]*\) .*/\1: \2/p'
The -n means "don't print by default". The /memory_total=/ matches the lines you're after; the s/// content is the same as before. I removed the g suffix that was there previously; the regex would never match multiple times anyway. I added the p to print the line when the substitution occurs.
This question already has answers here:
Using different delimiters in sed commands and range addresses
(3 answers)
Closed 1 year ago.
I have a Visual Studio project, which is developed locally. Code files have to be deployed to a remote server. The only problem is the URLs they contain, which are hard-coded.
The project contains URLs such as ?page=one. For the link to be valid on the server, it must be /page/one .
I've decided to replace all URLs in my code files with sed before deployment, but I'm stuck on slashes.
I know this is not a pretty solution, but it's simple and would save me a lot of time. The total number of strings I have to replace is fewer than 10. A total number of files which have to be checked is ~30.
An example describing my situation is below:
The command I'm using:
sed -f replace.txt < a.txt > b.txt
replace.txt which contains all the strings:
s/?page=one&/pageone/g
s/?page=two&/pagetwo/g
s/?page=three&/pagethree/g
a.txt:
?page=one&
?page=two&
?page=three&
Content of b.txt after I run my sed command:
pageone
pagetwo
pagethree
What I want b.txt to contain:
/page/one
/page/two
/page/three
The easiest way would be to use a different delimiter in your search/replace lines, e.g.:
s:?page=one&:pageone:g
You can use any character as a delimiter that's not part of either string. Or, you could escape it with a backslash:
s/\//foo/
Which would replace / with foo. You'd want to use the escaped backslash in cases where you don't know what characters might occur in the replacement strings (if they are shell variables, for example).
The s command can use any character as a delimiter; whatever character comes after the s is used. I was brought up to use a #. Like so:
s#?page=one&#/page/one#g
A very useful but lesser-known fact about sed is that the familiar s/foo/bar/ command can use any punctuation, not only slashes. A common alternative is s#foo#bar#, from which it becomes obvious how to solve your problem.
add \ before special characters:
s/\?page=one&/page\/one\//g
etc.
In a system I am developing, the string to be replaced by sed is input text from a user which is stored in a variable and passed to sed.
As noted earlier on this post, if the string contained within the sed command block contains the actual delimiter used by sed - then sed terminates on syntax error. Consider the following example:
This works:
$ VALUE=12345
$ echo "MyVar=%DEF_VALUE%" | sed -e s/%DEF_VALUE%/${VALUE}/g
MyVar=12345
This breaks:
$ VALUE=12345/6
$ echo "MyVar=%DEF_VALUE%" | sed -e s/%DEF_VALUE%/${VALUE}/g
sed: -e expression #1, char 21: unknown option to `s'
Replacing the default delimiter is not a robust solution in my case as I did not want to limit the user from entering specific characters used by sed as the delimiter (e.g. "/").
However, escaping any occurrences of the delimiter in the input string would solve the problem.
Consider the below solution of systematically escaping the delimiter character in the input string before having it parsed by sed.
Such escaping can be implemented as a replacement using sed itself, this replacement is safe even if the input string contains the delimiter - this is since the input string is not part of the sed command block:
$ VALUE=$(echo ${VALUE} | sed -e "s#/#\\\/#g")
$ echo "MyVar=%DEF_VALUE%" | sed -e s/%DEF_VALUE%/${VALUE}/g
MyVar=12345/6
I have converted this to a function to be used by various scripts:
escapeForwardSlashes() {
# Validate parameters
if [ -z "$1" ]
then
echo -e "Error - no parameter specified!"
return 1
fi
# Perform replacement
echo ${1} | sed -e "s#/#\\\/#g"
return 0
}
this line should work for your 3 examples:
sed -r 's#\?(page)=([^&]*)&#/\1/\2#g' a.txt
I used -r to save some escaping .
the line should be generic for your one, two three case. you don't have to do the sub 3 times
test with your example (a.txt):
kent$ echo "?page=one&
?page=two&
?page=three&"|sed -r 's#\?(page)=([^&]*)&#/\1/\2#g'
/page/one
/page/two
/page/three
replace.txt should be
s/?page=/\/page\//g
s/&//g
please see this article
http://netjunky.net/sed-replace-path-with-slash-separators/
Just using | instead of /
Great answer from Anonymous. \ solved my problem when I tried to escape quotes in HTML strings.
So if you use sed to return some HTML templates (on a server), use double backslash instead of single:
var htmlTemplate = "<div style=\\"color:green;\\"></div>";
A simplier alternative is using AWK as on this answer:
awk '$0="prefix"$0' file > new_file
You may use an alternative regex delimiter as a search pattern by backs lashing it:
sed '\,{some_path},d'
For the s command:
sed 's,{some_path},{other_path},'
I have a file named check.txt which has the below contents:
$ cat check.txt
~/bin/tibemsadmin -server $URL-user $USER -password $PASWRD
$
I have a main script where the values of $URL, $USER, $PASWRD are obtained from the main script. I want to use the SED utility to replace the $URL, $USER, $PASWRD to the actual values in the check.txt.
I am trying like this but it fails.
emsurl=tcp://myserver:3243
emsuser=test
emspasswd=new
sed s/$URL/${emsurl}/g check.txt >> check_new.txt
sed s/$USER/${emsuser}/g check.txt_new.txt >> check_new_1.txt
sed s/PASWRD/${emspasswd}/g check_new_1.txt >> final.txt
My final.txt output is desired as below:
~/bin/tibemsadmin -server tcp://myserver:3243 -user test -password new
Could you please help me?
You have to be rather careful with your use of quotes. You also need to learn how to do multiple operations in a single pass, and/or how to use pipes.
emsurl=tcp://myserver:3243
emsuser=test
emspasswd=new
sed -e "s%\$URL%${emsurl}%g" \
-e "s%\$USER%${emsuser}%g" \
-e "s%\$PASWRD%${emspasswd}%g" check.txt >final.txt
Your problem is that the shell expanded the '$URL' in your command line (probably to nothing), meaning that sed got to see something other than what you intended. By escaping the $ with the \, sed gets to see what you intended.
Note that I initially used / as the separator in the substitute operations; however, as DarkDust rightly points out, that won't work since there are slashes in the URLs. My normal fallback character is % - as now shown - but that can appear in some URLs and might not be appropriate. I'd probably use a control character, such as control-A, if I needed to worry about that - or I'd use Perl which would be able to play without getting confused.
You can also combine the three separate -e expressions into one with semi-colons replacing them. However, I prefer the clarity of the three operations clearly separated.
You could take a slightly different approach by modifying your main script as follows :-
export URL="tcp://myserver:3243"
export USER=test
export PASWRD=new
. ./check.txt
This sets up the variables and then runs check.txt within the context of your main script
Although you don't say what's failing I guess I see the problems.
I suggest you do this:
sed "s|\$URL|${emsurl}|g"
That is, the first $ needs to be escaped because you want it literally. Then, instead of / I suggest you use | (pipe) as delimiter since it's not used in your strings. Finally, use " to ensure the content is interpreted as string by the shell.
You can then pipe everything together to not need any temporary files:
sed "s|\$URL|${emsurl}|g" | sed "s|\$USER|${emsuser}|g" | sed "s|\$PASSWRD|${emspasswd}|g"
Variable substitution should be outside sed expression and '$' should be escaped; in your case something like this:
sed -e 's/\$URL/'$emsurl'/g' -e 's/\$USER/'$emsuser'/g' -e 's/\$PASSWORD/'$emaspasswd'/g'
Anyway in your place I would avoid using $ to match placeholders in a template file, because it's causing confusion with BASH variables, use a different pattern instead (for instance #URL#).
I have the following: param="/var/tmp/test"
I need to replace the word test with another word such as new_test
need a smart way to replace the last word after "/" with sed
echo 'param="/var/tmp/test"' | sed 's/\/[^\/]*"/\/REPLACEMENT"/'
param="/var/tmp/REPLACEMENT"
echo '/var/tmp/test' | sed 's/\/[^\/]*$/\/REPLACEMENT/'
/var/tmp/REPLACEMENT
Extracting bits and pieces with sed is a bit messy (as Jim Lewis says, use basename and dirname if you can) but at least you don't need a plethora of backslashes to do it if you are going the sed route since you can use the fact that the delimiter character is selectable (I like to use ! when / is too awkward, but it's arbitrary):
$ echo 'param="/var/tmp/test"' | sed ' s!/[^/"]*"!/new_test"! '
param="/var/tmp/new_test"
We can also extract just the part that was substituted, though this is easier with two substitutions in the sed control script:
$ echo 'param="/var/tmp/test"' | sed ' s!.*/!! ; s/"$// '
test
You don't need sed for this...basename and dirname are a better choice for assembling or disassembling pathnames. All those escape characters give me a headache....
param="/var/tmp/test"
param_repl=`dirname $param`/newtest
It's not clear whether param is part of the string that you need processed or it's the variable that holds the string. Assuming the latter, you can do this using only Bash (you don't say which shell you're using):
shopt -s extglob
param="/var/tmp/test"
param="${param/%\/*([^\/])//new_test}"
If param= is part of the string:
shopt -s extglob
string='param="/var/tmp/test"'
string="${string/%\/*([^\/])\"//new}"
This might work for you:
echo 'param="/var/tmp/test"' | sed -r 's#(/(([^/]*/)*))[^"]*#\1newtest#'
param="/var/tmp/newtest"
I need to replace several URLs in a text file with some content dependent on the URL itself. Let's say for simplicity it's the first line of the document at the URL.
What I'm trying is this:
sed "s/^URL=\(.*\)/TITLE=$(curl -s \1 | head -n 1)/" file.txt
This doesn't work, since \1 is not set. However, the shell is getting called. Can I somehow push the sed match variables to that subprocess?
The accept answer is just plain wrong. Proof:
Make an executable script foo.sh:
#! /bin/bash
echo $* 1>&2
Now run it:
$ echo foo | sed -e "s/\\(foo\\)/$(./foo.sh \\1)/"
\1
$
The $(...) is expanded before sed is run.
So you are trying to call an external command from inside the replacement pattern of a sed substitution. I dont' think it can be done, the $... inside a pattern just allows you to use an already existent (constant) shell variable.
I'd go with Perl, see the /e option in the search-replace operator (s/.../.../e).
UPDATE: I was wrong, sed plays nicely with the shell, and it allows you do to that. But, then, the backlash in \1 should be escaped. Try instead:
sed "s/^URL=\(.*\)/TITLE=$(curl -s \\1 | head -n 1)/" file.txt
Try this:
sed "s/^URL=\(.*\)/\1/" file.txt | while read url; do sed "s#URL=\($url\)#TITLE=$(curl -s $url | head -n 1)#" file.txt; done
If there are duplicate URLs in the original file, then there will be n^2 of them in the output. The # as a delimiter depends on the URLs not including that character.
Late reply, but making sure people don't get thrown off by the answers here -- this can be done in gnu sed using the e command. The following, for example, decrements a number at the beginning of a line:
echo "444 foo" | sed "s/\([0-9]*\)\(.*\)/expr \1 - 1 | tr -d '\n'; echo \"\2\";/e"
will produce:
443 foo