With Sed, I want to use "!" to exclude lines that matches "he". Here is an example.
echo "hello" |sed "/he/!s/hello/hi/"
To my surprise, my ubuntu 14 returns
"bash !s/hello/hi: event not found"
error. Any ideas? How could I exclude line ranges corresponding to a pattern with Sed?
You have history expansion enabled. You need to disable it with set +H.
Example
Let's enable history expansion and run your command:
$ set -H
$ echo "hello" |sed "/he/!s/hello/hi/"
bash: !s/hello/hi/: event not found
Now, let's disable it and observe that the command now runs correctly and without error:
$ set +H
$ echo "hello" |sed "/he/!s/hello/hi/"
hello
Alternative
If you want to keep history expansion enabled, then single-quote your string:
$ set -H
$ echo "hello" |sed '/he/!s/hello/hi/'
hello
Related
I already know that sed uses own approach to deal with single quote but I think it still possible to use it in my automation script.
I had to replace value of fingerprint in Saltstack config file.
Current value:
#master_finger: ''
Target value
master_finger: 'some:value'
My current command which doesn't work:
$ sed -i 's/#master_finger: ''/master_finger: 'some:value'/g' /etc/salt/minion
returns:
master_finger: some:value''
How can I solve this?
just use the double quotes to enclose the script.
$ echo "#master_finger: ''" | sed "s/#master_finger: ''/master_finger: 'some:value'/"
master_finger: 'some:value'
It's not sed that's making handling of 's difficult, it's the shell because the shell does not allow 's within any '-quoted string, including scripts.
You could save the sed script in a file and run it with -f or use a here document:
$ sed -f- file <<'EOF'
s/#master_finger: ''/master_finger: 'some:value'/g
EOF
master_finger: 'some:value'
To see the difference between the above and #karakfas suggestion:
$ sed -f- file <<'EOF'
s/#master_finger: ''/master_finger: '$(date)'/g
EOF
master_finger: '$(date)'
$ sed "s/#master_finger: ''/master_finger: '$(date)'/" file
master_finger: 'Sun Feb 14 06:50:43 CST 2021'
and imagine if date was replace by rm -rf * or something worse.
Also consider:
$ sed 's/#master_finger: '\'\''/master_finger: '\''$(date)'\''/' file
master_finger: '$(date)'
I'm trying to migrate this working command
docker-compose $(find docker-compose* | sed -e "s/^/-f /") up -d --remove-orphans
from bash to fish. The intention of this command is to get this
docker-compose -f docker-compose.backups.yml ... -f docker-compose.wiki.yml up -d --remove-orphans
My naive try
docker-compose (find docker-compose* | sed -e "s/^/-f /") up -d --remove-orphans
is not working, though. The error is:
ERROR: .FileNotFoundError: [Errno 2] No such file or directory: './ docker-compose.backups.yml'
What is the correct translation?
The difference in behavior is due to the fact fish, sanely, only splits the output of a command capture on line boundaries. Whereas POSIX shells like bash split it on whitespace by default. That is, POSIX shells split the output of $(...) on the value of $IFS which is space, tab, and newline by default.
There are several ways to rewrite that command so it works in fish. The one that requires the smallest change is to change the sed to insert a newline between the -f and the filename:
docker-compose (find docker-compose* | sed -e "s/^/-f\n/") up -d --remove-orphans
I am trying to add a line in a file using sed after first match. I looked my threads online, addressing the same issue and tried below versions of the command:
sudo sed -e '/cfg_file/cfg_file='$NEW_FILE -e '/cfg_file/cfg_file=/q' MAIN_CONF_FILE
sudo sed -i '0,/cfg_file/ a\cfg_file='$NEW_FILE $MAIN_CONF_FILE
sudo sed -i '1s/cfg_file/cfg_file='$NEW_FILE $MAIN_CONF_FILE
sudo sed -i '1/cfg_file/s/cfg_file='$NEW_FILE $MAIN_CONF_FILE
Unfortunately, nothing worked for me. Either they show error, in case of point 3, or show similar behavior of adding lines after each match.
SAMPLE FILE
cfg_file=some_line1
cfg_file=some_line2
Now I want to add a line after first match of cg_file, like below.
EXPECTED RESULT
cfg_file=some_line1
cfg_file=my_added_line_after_first_match_only.
cfg_file=some_line2
Help me in adding line after first match and correcting my command.
Since you're on Ubuntu, you are using GNU sed. GNU sed has some weird features and some useful ones; you should ignore the weird ones and use the useful ones.
In context, the useful one is ranges starting at line 0. Weird ones are the way it messes with a, i and c commands.
MAIN_CONF_FILE=/tmp/copy.of.main.config.file
NEWFILE="my_added_line_after_first_match_only."
sed -e '0,/^cfg_file=/ { /^cfg_file/ a\' \
-e "cfg_file=$NEWFILE" \
-e '}' \
"$MAIN_CONF_FILE"
In classic sed, the a command is followed by backslash-newline, and each subsequent line of the script is appended up to and including the first line without a backslash at the end (and the backslash is removed). Each -e argument functions as a line in the script. Distinguish between the shell lines escaped with backslash at the end and the sed script lines with backslash at the end.
Example at work
$ cat /tmp/copy.of.main.config.file | so
cfg_file=some_line1
cfg_file=some_line2
$ cat script.sh
MAIN_CONF_FILE=/tmp/copy.of.main.config.file
NEWFILE="my_added_line_after_first_match_only."
SED=/opt/gnu/bin/sed
${SED} \
-e '0,/^cfg_file=/ { /^cfg_file/ a\' \
-e "cfg_file=$NEWFILE" \
-e '}' \
"$MAIN_CONF_FILE"
$ bash script.sh
cfg_file=some_line1
cfg_file=my_added_line_after_first_match_only.
cfg_file=some_line2
$
This is based on your attempt 2, but avoids some of the weird stuff.
Basic sanity
As I noted, it is not sensible to experiment with sudo and the -i option to sed. You don't use those until you know that the script will do the job correctly. It is dangerous to do anything as root via sudo. It is doubly dangerous when you don't know whether what you're trying to use will work. Don't risk wrecking your system.
I'm using here document of sh to run some commands. now I want to parse the output of those commands using awk. However, everytime I execute it, I get the output of the command append with something like this "% No such child process"
This is how my script looks like.
#!/bin/sh
com = "sudo -u username /path/of/file -l"
$com <<EOF | awk '{print $0}'
Commands.
.
.
.
EOF
How am I going to use heredoc and pipeline without appending that unwanted string?
Thanks
Your variable assignment is wrong in a couple of ways. First, you aren't actually assigning a variable; you're trying to run a command named com whose arguments are = and a string "sudo ...". Spaces must not be used on either side of the =:
com="sudo ..."
Second, command lines should not be stored in a variable; the shell's parser can only make that work they way you intend for very simple commands. Type the command out in full, or use a shell function.
com () {
sudo -u username /path/to/file -l
}
com <<EOF | awk '{print $0}'
...
EOF
There's no problem, check :
$ cat <<EOF | awk '{print $1}'
a b c
1 2 3
EOF
a
1
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