Replace 3 lines with another line SED Syntax - sed

This is a simple question, I'm not sure if i'm able to do this with sed/awk
How can I make sed search for these 3 lines and replace with a line with a determined string?
<Blarg>
<Bllarg>
<Blllarg>
replace with
<test>
I tried with sed "s/<Blarg>\n<Bllarg>\n<Blllarg>/<test>/g" But it just don't seem to find these lines. Probably something with my break line character (?) \n. Am I missing something?

Because sed usually handles only one line at a time, your pattern will never match. Try this:
sed '1N;$!N;s/<Blarg>\n<Bllarg>\n<Blllarg>/<test>/;P;D' filename

This might work for you:
sed '/<Blarg>/ {N;N;s/<Blarg>\n<Bllarg>\n<Blllarg>/<test>/}' <filename>
It works as follows:
Search the file till <Blarg> is found
Then append the two following lines to the current pattern space using N;N;
Check if the current pattern space matches <Blarg>\n<Bllarg>\n<Blllarg>
If so, then substitute it with <test>

You can use range addresses with regular expressions an the c command, which does exactly what you are asking for:
sed '/<Blarg>/,/<Blllarg>/c<test>' filename

Related

Insert specific lines from file before first occurrence of pattern using Sed

I want to insert a range of lines from a file, say something like 210,221r before the first occurrence of a pattern in a bunch of other files.
As I am clearly not a GNU sed expert, I cannot figure how to do this.
I tried
sed '0,/pattern/{210,221r file
}' bunch_of_files
But apparently file is read from line 210 to EOF.
Try this:
sed -r 's/(FIND_ME)/PUT_BEFORE\1/' test.text
-r enables extendend regular expressions
the string you are looking for ("FIND_ME") is inside parentheses, which creates a capture group
\1 puts the captured text into the replacement.
About your second question: You can read the replacement from a file like this*:
sed -r 's/(FIND_ME)/`cat REPLACEMENT.TXT`\1/' test.text
If replace special characters inside REPLACEMENT.TXT beforehand with sed you are golden.
*= this depends on your terminal emulator. It works in bash.
In https://stackoverflow.com/a/11246712/4328188 CodeGnome gave some "sed black magic" :
In order to insert text before a pattern, you need to swap the pattern space into the hold space before reading in the file. For example:
sed '/pattern/ {
h
r file
g
N
}' in
However, to read specific lines from file, one may have to use a two-calls solution similar to dummy's answer. I'd enjoy knowing of a one-call solution if it is possible though.

Using sed to convert singular/plural words into uppercase

Using one sed command I'm trying to convert all occurrences of test and tests found in a .txt file into all caps. I also want to print only the converted lines, so I'm using -n. I've been playing around for it for over an hour. The problem is that I'm able to convert one or the other (either test or tests) but not both.
Any help would be so greatly appreciated. Thank you!
Use this
sed -e 's/tests/TESTS/g; s/test/TEST/g; T; p;' input.txt
The semicolons let you execute multiple commands.
This might work for you (GNU sed):
sed 's/\<tests\?\>/\U&/gp;d' file
This will uppercase words (\<....\>) that begin test with an optional s (s\?).
Sorry for the late response, but here is hopefully an understandable one with basic regex (no extended regex):
sed 's:\<test\(s*\)\>:TEST\1:g' < inputFile.txt > outputFile.txt; cat outputFile.txt | grep -n TEST
Explanation:
: delimiter (instead of usual /)
\<test\> matches test. The character before the first t can be any character except a letter, number or underscore. Same applies for the character after the last t.
\(\) remember what is inside the parenthesis.
s* match zero or more s's.
\1 used to insert first remembered match (i.e. any number of s's matched).
The rest is hopefully clear. Otherwise leave a comment.

about use sed Modify the file?

I have a question about using sed to modify file. My file content:
<data-value name="WLS_INSTALL_DIR" value="/home/Oracle/wlserver_10.3">
I want to replace the content of field value="/home/Oracle/wlserver_10.3"
to get this result:
<data-value name="WLS_INSTALL_DIR" value="/u03/Middle_home/Oracle/wlserver_10.3">
I use sed:
sed "6 i/^value=/>/s/value= />\(.*\)/value=\"\/u03\/Oracle/Middleware/wlserver_10.3"\" \/\ /u03/silent.xml
Your sed script has a number of issues.
First off, anything that looks like 6istuff will simply write everything after i ("insert") verbatim as a new line before the sixth line. (Some dialects require a newline after the i and will basically do nothing.)
Secondly, ^value= does not match your input; it would only select a line starting with the string value= (the ^ metacharacter means beginning of line).
Thirdly, the /> in your subsitution regex terminates the substitution and so everything from > onwards is parsed as invalid flags for the substitution. I cannot see the purpose of this part, anyway; it doesn't match your data, and so the regex fails.
What remains after removing all these superfluous and erroneous details is a more or less useful sed script. (I assume the 6 to address only the sixth line of input is intentional, although you don't mention this in the question at all.) I have made some additional minor improvements, such as using % as the substitution delimiter and tightening the regex so that it only ever substitutes a double-quoted value.
sed '6s%value="[^"]*"%value="/u03/Oracle/Middleware/wlserver_10.3"%' /u03/silent.xml
Better than 6 would perhaps be to identify the line with /name="WLS_INSTALL_DIR"/.
Still, as alluded to in a comment, the proper way to manipulate XML is with a dedicated tool such as xsltproc.
Try:
sed 's|/home|/u03/Middle_home|'

Matching strings even if they start with white spaces in SED

I'm having issues matching strings even if they start with any number of white spaces. It's been very little time since I started using regular expressions, so I need some help
Here is an example. I have a file (file.txt) that contains two lines
#String1='Test One'
String1='Test Two'
Im trying to change the value for the second line, without affecting line 1 so I used this
sed -i "s|String1=.*$|String1='Test Three'|g"
This changes the values for both lines. How can I make sed change only the value of the second string?
Thank you
With gnu sed, you match spaces using \s, while other sed implementations usually work with the [[:space:]] character class. So, pick one of these:
sed 's/^\s*AWord/AnotherWord/'
sed 's/^[[:space:]]*AWord/AnotherWord/'
Since you're using -i, I assume GNU sed. Either way, you probably shouldn't retype your word, as that introduces the chance of a typo. I'd go with:
sed -i "s/^\(\s*String1=\).*/\1'New Value'/" file
Move the \s* outside of the parens if you don't want to preserve the leading whitespace.
There are a couple of solutions you could use to go about your problem
If you want to ignore lines that begin with a comment character such as '#' you could use something like this:
sed -i "/^\s*#/! s|String1=.*$|String1='Test Three'|g" file.txt
which will only operate on lines that do not match the regular expression /.../! that begins ^ with optional whiltespace\s* followed by an octothorp #
The other option is to include the characters before 'String' as part of the substitution. Doing it this way means you'll need to capture \(...\) the group to include it in the output with \1
sed -i "s|^\(\s*\)String1=.*$|\1String1='Test Four'|g" file.txt
With GNU sed, try:
sed -i "s|^\s*String1=.*$|String1='Test Three'|" file
or
sed -i "/^\s*String1=/s/=.*/='Test Three'/" file
Using awk you could do:
awk '/String1/ && f++ {$2="Test Three"}1' FS=\' OFS=\' file
#String1='Test One'
String1='Test Three'
It will ignore first hits of string1 since f is not true.

Use Sed to modify a line that has an initial space and contains a comma

This should be extremely simple, but for the life of me I just can't get gnu-sed to do it this afternoon.
The file in question has lines that look like this:
PART NUMBER PART NUMBER QUANTITY WEIGHT -999 -4,999 -9,999
w/ UL APPROVAL
MIN-3
I need to prepend every line like the "MIN-3" line with a ">" character, and the only thing specifically differentiating those lines from the others are two things:
The first character is a space " ".
The lines do not contain a comma.
I've tried mostly things like any of the following:
/^ +[^,]+$/ s/^/>/
/^ +[\w\-]+$/ s/^/>/
/^ +(\w|\-)+$/ s/^/>/
I will admit, I am somewhat new to sed. :)
Edit: Answers that use perl, or awk could also be appreciated, though my initial target is sed.
try this:
sed '/^ [^,]*$/s/^/>/'
the output is, only the line with MIN-3 with leading >
sed default uses basic regex. so the + should be \+ in your script. I think that could be the problem killing your time. You could add -r however, to let sed use extended-regex.
According to your description this should do:
sed 's/^\([ ][^,]*\)$/> \1/' input
which matches the complete line if the line starts with a space and then contains anything but a comma until the end.
Here is a simple answer:
sed 's/^ [^,]*$/>&/'