[SOLVED] Sed help

dilip_d21 · 11-12-2021, 03:26 AM

Hallo Team , Need a small help in sed 4.7

cat pom.xml

<artifactId>XXX-restapi-commons</artifactId> (line 10)
<version>1.0.88</version> (line 11)

[code]

sed -i \'/<artifactId>XXX-restapi-commons<\\/artifactId>/!b;n;c<version>\'$a\'</version>\' pom.xml

artifactId: No such file or directory

[code]

The above command works fine in sed 4.4 and the same is not working in 4.7 ubuntu (can some one point what is the mistake here ??

I just want to replace what ever version in line11 with the value in the variable a .

Thanks in advance

pan64 · 11-12-2021, 04:01 AM

please use code tags (and edit your post).
Also would be nice to explain what's happened with sed 4.7.

Turbocapitalist · 11-12-2021, 04:05 AM

Quote:

Originally Posted by dilip_d21

I just want to replace what ever version in line11 with the value in the variable a .

Then you'll want a different tool than sed, as it is no good at parsing XML. Try xmlstarlet instead. Or else write a short Python or Perl script. Either way, you need a proper XML parser for the task.

dilip_d21 · 11-12-2021, 04:08 AM

@pan64 , i have updated the error in the question itself , thanks

Turbocapitalist · 11-12-2021, 04:11 AM

You've escaped the single quotes. Leave the plain and the string "artifactId" won't get treated like a redirected file name. Again though sed is not the right tool for this job.

Which distro is this on, including version?

dilip_d21 · 11-12-2021, 04:18 AM

@Turbocapitalist , thanks i am not unfortunately good in python/perl ,

NAME="Ubuntu"
VERSION="20.04.3 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.3 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal

pan64 · 11-12-2021, 04:27 AM

Quote:

Originally Posted by dilip_d21

@pan64 , i have updated the error in the question itself , thanks

that is definitely not related to sed version change. As it was explained the syntax of that line is incorrect.

dilip_d21 · 11-12-2021, 04:33 AM

@pan64 , that sed command is working in Linux sed 4.4 and i am trying to migrate the code to ubuntu seb 4.7 and i face the issue , thanks

shruggy · 11-12-2021, 04:44 AM

I don't know what shell you were using in the Linux you're trying to migrate the code from, but in Bash the quoting is just plain wrong. This is not a sed issue.

Code:

$ cat pom.xml.part
<artifactId>XXX-restapi-commons</artifactId>
<version>1.0.88</version>
$ sed '\|<artifactId>XXX-restapi-commons</artifactId>|!b;n;c<version>'"$(sed --version|head -1)"'</version>' pom.xml.part
<artifactId>XXX-restapi-commons</artifactId>
<version>sed (GNU sed) 4.8</version>

This post shows how to do it with xmlstarlet.

Code:

$ cat pom.xml.part
<dependency>
  <artifactId>XXX-restapi-commons</artifactId>
  <version>1.0.88</version>
  <scope>test</scope>
</dependency>
$ xmlstarlet ed -u "//artifactId[text()='XXX-restapi-commons']/following-sibling::version" -v NEW pom.xml.part
<?xml version="1.0"?>
<dependency>
  <artifactId>XXX-restapi-commons</artifactId>
  <version>NEW</version>
  <scope>test</scope>
</dependency>

dilip_d21 · 11-12-2021, 05:16 AM

Thanks shruggy , that worked , it just saw the mistake in the statement , thanks @Turbocapitalist and @pan64.

have a nice day , Cheers

Turbocapitalist · 11-12-2021, 05:19 AM

No problem. However, do take a good look at the xmlstarlet tool show in post #9, at least at its use of XPaths. Knowledge of XPaths is a highly portable skill and can be used for processing XML even in your own Python or Perl scripts. regex is the wrong tool here. XPath is one of the suitable tools.

pan64 · 11-12-2021, 05:22 AM

Quote:

Originally Posted by dilip_d21

@pan64 , that sed command is working in Linux sed 4.4 and i am trying to migrate the code to ubuntu seb 4.7 and i face the issue , thanks

again, the error message you posted:

Quote:

artifactId: No such file or directory

is not related to any sed version, that is a simple syntax error.

From the other hand it looks like your question has been answered, in that case please mark the thread as solved.

shruggy · 11-12-2021, 05:36 AM

To expand on what Turbocapitalist says. The problem with your code is that it assumes a rigid structure of input data which XML isn't. While the same xmlstarlet command can easily handle situations where it fed an equivalent, but differently formatted pom.xml. E.g. when order of <scope> and <version> is reversed:

Code:

$ cat pom.xml.part
<dependency>
  <artifactId>XXX-restapi-commons</artifactId>
  <scope>test</scope>
  <version>1.0.88</version>
</dependency>
$ xmlstarlet ed -u "//artifactId[text()='XXX-restapi-commons']/following-sibling::version" -v NEW pom.xml.part
<?xml version="1.0"?>
<dependency>
  <artifactId>XXX-restapi-commons</artifactId>
  <scope>test</scope>
  <version>NEW</version>
</dependency>

Or when <artifactId> and <version> are on the same line:

Code:

$ cat pom.xml.part
<dependency>
  <artifactId>XXX-restapi-commons</artifactId><version>1.0.88</version>
  <scope>test</scope>
</dependency>
$ xmlstarlet ed -u "//artifactId[text()='XXX-restapi-commons']/following-sibling::version" -v NEW pom.xml.part
<?xml version="1.0"?>
<dependency>
  <artifactId>XXX-restapi-commons</artifactId>
  <version>NEW</version>
  <scope>test</scope>
</dependency>

and so on.

syg00 · 11-12-2021, 05:47 AM

All that said, a properly constructed (simple) ERE sed would do just fine here. I must admit I would do that rather than faff around with trying to relearn xmlstarlet when I need it maybe once a year.

Each to their own ... :shrug:

MadeInGermany · 11-12-2021, 07:05 AM

Code:

sed -i '
# sed code embedded in a multi-lined string
  \#<artifactId>XXX-restapi-commons</artifactId>#!b
  n; c<version>'"$a"'</version>
' pom.xml

In the shell a 'string in strong quotes' prevents all kind of substitutions.
Only the ' itself need to be escaped as '\'' where the first ' ends the string, followed by a \' outside, followed by a ' that starts another string.
Likewise
'"$a"'
where the first ' ends the string, followed by $a in "quotes" (that allows a $expression substitution only), followed by a ' that starts another string.

The sed code makes the assumption that version is always on the next line. An xml parser is safer.