If pattern matched delete newline character in that line - awk

Let say pattern is string "Love"
input
This is some text
Love this or that
He is running like a rabbit
output
This is some text
Love this or thatHe is running like a rabbit
I've noticed that sed is very unpleasant for deleting newline characters, any idea?

You can use this:
sed '/^Love/{N;s/\n//;}' love.txt
details:
/^Love/ identifies the line to treat, if you like you can use /[Ll]ove/ instead
N adds the next line to the pattern space. After this command the pattern space contains Love this or that\nHe is running like a rabbit
s/\n// replaces the newline character

Perl:
$ perl -pe 's/^(Love[^\n]*)\n/\1/' file.txt
This is some text
Love this or thatHe is running like a rabbit
Or, if the intent is solely focused on the \n you can chomp based on a pattern:
$ perl -pe 'chomp if /^Love/' file.txt
This is some text
Love this or thatHe is running like a rabbit

$ awk '/Love/{printf "%s ",$0;next} 1' file
This is some text
Love this or that He is running like a rabbit
Explanation:
/Love/{printf "%s ",$0;next}
For lines that contain Love, the line is printed, via printf, without a newline. awk then starts over on the next line.
1
For lines that don't include Love, they are printed normally (with a newline). The 1 command is awk's cryptic shorthand for print normally.

Through Perl,
$ perl -pe 's/^Love.*\K\n//' file
This is some text
Love this or thatHe is running like a rabbit
\K discards previously matched characters.
OR
$ perl -pe '/^Love/ && s/\n//' file
This is some text
Love this or thatHe is running like a rabbit
If a line starts with the string Love, then it removes the newline character from that line.

Here is another awkvariation:
awk '{ORS=(/Love/?FS:RS)}1' file
This is some text
Love this or that He is running like a rabbi
This change the ORS based on the pattern
Here are some other awk
awk '{printf "%s%s",$0,(/Love/?FS:RS)}' file
This is some text
Love this or that He is running like a rabbit
If line has Love in it use FS as separator, else use RS
This should work too, but use the first one.
awk '{printf "%s"(/Love/?FS:RS),$0}' file

Related

Delete everything before first pattern match with sed/awk

Let's say I have a line looking like this:
/Users/random/354765478/Tests/StoreTests/Base64Tests.swift
In this example, I would like to get the result:
Tests/StoreTests/Base64Tests.swift
How can I do if I want to get everything before the first pattern match (either Sources or Tests) using sed or awk?
I am using sed 's/^.*\(Tests.*\).*$/\1/' right now but it's falling:
echo '/Users/random/354765478/Tests/StoreTests/Base64Tests.swift' | sed 's/^.*\(Tests\)/\1/'
Tests.swift
Here's another example using Sources (which seems to work):
echo '/Users/random/741672469/Sources/Store/StoreDataSource.swift' | sed 's/^.*\(Sources\)/\1/'
Sources/Store/StoreDataSource.swift
I would like to get everything before the first, and not the last Sources or Tests pattern match.
Any help would be appreciated!
How can I do if I want to get everything before the first pattern match (either Sources or Tests).
Easier to use a grep -o here:
grep -Eo '(Sources|Tests)/.*' file
Tests/StoreTests/Base64Tests.swift
Sources/Store/StoreDataSource.swift
# where input file is
cat file
/Users/random/354765478/Tests/StoreTests/Base64Tests.swift
/Users/random/741672469/Sources/Store/StoreDataSource.swift
Breakdown:
Regex pattern (Sources|Tests)/.* match any text that starts with Sources/ or Tests/ until end of the line.
-E: enables extended regex mode
-o: prints only matched text instead of full line
Alternatively you may use this awk as well:
awk 'match($0, /(Sources|Tests)\/.*/) {
print substr($0, RSTART)
}' file
Tests/StoreTests/Base64Tests.swift
Sources/Store/StoreDataSource.swift
Or this sed:
sed -E 's~.*/((Sources|Tests)/.*)~\1~' file
Tests/StoreTests/Base64Tests.swift
Sources/Store/StoreDataSource.swift
With your shown samples please try following GNU grep. This will look for very first match of /Sources OR /Tests and then print values from these strings to till end of the value.
grep -oP '^.*?\/\K(Sources|Tests)\/.*' Input_file
Using sed
$ sed -E 's~([^/]*/)+((Tests|Sources).*)~\2~' input_file
Tests/StoreTests/Base64Tests.swift
would like to get everything before the first, and not the last
Sources or Tests pattern match.
First thing is to understand reason of that, you are using
sed 's/^.*\(Tests.*\).*$/\1/'
observe that * is greedy, i.e. it will match as much as possible, therefore it will always pick last Tests, if it would be non-greedy it would find first Tests but sed does not support this, if you are using linux there is good chance that you have perl command which does support that, let file.txt content be
/Users/random/354765478/Tests/StoreTests/Base64Tests.swift
then
perl -p -e 's/^.*?(Tests.*)$/\1/' file.txt
gives output
Tests/StoreTests/Base64Tests.swift
Explanation: -p -e means engage sed-like mode, alterations in regular expression made: brackets no longer require escapes, first .* (greedy) changed to .*? (non-greedy), last .* deleted as superfluous (observe that capturing group will always extended to end of line)
(tested in perl 5, version 30, subversion 0)

Git URL - Pull out substring via Shell (awk & sed)?

I have got the following URL:
https://xcg5847#git.rz.bankenit.de/scm/smat/sma-mes-test.git
I need to pull out smat-mes-test and smat:
git config --local remote.origin.url|sed -n 's#.*/\([^.]*\)\.git#\1#p'
sma-mes-test
This works. But I also need the project name, which is smat
I am not really familiar to complex regex and sed, I was able to find the other command in another post here. Does anyone know how I am able to extract the smat value here?
With your shown samples please try following awk code. Simple explanation would be, setting field separator(s) as / and .git for all the lines and in main program printing 3rd last and 3nd last elements from the line.
your_git_command | awk -F'/|\\.git' '{print $(NF-2),$(NF-1)}'
Your sed is pretty close. You can just extend it to capture 2 values and print them:
git config --local remote.origin.url |
sed -E 's~.*/([^/]+)/([^.]+)\.git$~\1 \2~'
smat sma-mes-test
If you want to populate shell variable using these 2 values then use this read command in bash:
read v1 v2 < <(git config --local remote.origin.url |
sed -E 's~.*/([^/]+)/([^.]+)\.git$~\1 \2~')
# check variable values
declare -p v1 v2
declare -- v1="smat"
declare -- v2="sma-mes-test"
Using sed
$ sed -E 's#.*/([^/]*)/#\1 #' input_file
smat sma-mes-test.git
I would harness GNU AWK for this task following way, let file.txt content be
https://xcg5847#git.rz.bankenit.de/scm/smat/sma-mes-test.git
then
awk 'BEGIN{FS="/"}{sub(/\.git$/,"",$NF);print $(NF-1),$NF}' file.txt
gives output
smat sma-mes-test
Explanation: I instruct GNU AWK that field separator is slash character, then I replace .git (observe that . is escaped to mean literal dot) adjacent to end ($) in last field ($NF), then I print 2nd from end field ($(NF-1)) and last field ($NF), which are sheared by space, which is default output field separator, if you wish to use other character for that purpose set OFS (output field separator) in BEGIN. If you want to know more about NF then read 8 Powerful Awk Built-in Variables – FS, OFS, RS, ORS, NR, NF, FILENAME, FNR
(tested in gawk 4.2.1)
Why not sed 's!.*/\(.*/.*\)!\1!'?
string=$(config --local remote.origin.url | tail -c -21)
var1=$(echo "${string}" | cut -d'/' -f1)
var2=$(echo "${string}" | cut -d'/' -f2 | sed s'#\.git##')
If you have multiple urls with variable lengths, this will not work, but if you only have the one, it will.
var1=smat
var2=sma-mes-test.git
If I did have something variable, personally I would replace all of the forward slashes with carriage returns, throw them into a file, and then export the last and second last lines with ed, which would give me the two last segments of the url.
Regular expressions literally give me a migraine headache, but as long as I can get everything on its' own line, I can quite easily bypass the need for them entirely.

Awk-How remove pattern with brackets

I made a mistake, adding Ini file (Yes we're in 2022 :D) a section with errors
I added a line [End[edit=true]
How could remove this entire line using awk (I don't have any others choice 😕)
I don't understand how escape the [ in the AWK command line.
Could you please help me?
Thanks
I don't understand how escape the [ in the AWK command line.
If line is always literal [End[edit=true] then you do not need to, just request lines which are not that one following way, let file.ini content be
[someline=true]
[End[edit=true]
[another=true]
then
awk '$0!="[End[edit=true]"' file.ini
gives output
[someline=true]
[another=true]
Explanation: $0 denotes whole line, if it is not [End[edit=true] then it is printed.
(tested in GNU Awk 5.0.1)
A couple ideas where you escape the leading (left) brackets:
awk '/\[End\[edit=true]/ {next} 1' file
# or
awk '!/\[End\[edit=true]/' file
Once you've confirmed the results, and assuming you're using GNU awk, you can add -i inplace to update the file:
awk -i inplace '!/\[End\[edit=true]/' file

print dir path after matching its name with wildcards

Have been stuck with this little puzzle. Thank you in advance for helping.
I have a directory path and would like print its path after match.
like
echo /Users/user/Documents/terraform-shared-infra/services/history_book_test | awk -F "terraform-|tfRepo-" '{print $(NF)}'
echo /Users/user/Documents/tfRepo-shared-infra/services/history_book_test | awk -F "terraform-|tfRepo-" '{print $(NF)}'
output:
shared-infra/services/history_book_test
shared-infra/services/history_book_test
When i try to add wildcard in terraform-* it doesn't work.
I would like to print path after match with terraform-* or tfRepo*.
Like:
services/history_book_test
services/history_book_test/../.. so on.
with sed:
echo /Users/user/Documents/terraform-shared-infra/services/history_book_test | sed 's|.*terraform.\([^/]*\)/.*|\1|'
shared-infra
Have tried different ways with awk and grep but no luck. Any leads or idea that I can try. Please.
Thank you.
You're confusing regular expressions with globbing patterns. Both have wildcards and look similar but have quite different meanings and uses. regexps are used by text processing tools like grep, sed, and awk to match text in input strings while globbing patterns are used by shells to match file/directory names. For example, foo* in a regexp means fo followed by zero or more additional os while foo* in a globbing pattern means foo followed by zero or more other characters (which in a regexp would be foo.*). So never just say "wildcard", say "regexp wildcard" or "globbing wildcard" for clarity.
This might be what you're trying to do, using a sed that has a -E arg to enable EREs, e.g. GNU or BSD sed:
$ sed -E 's:.*/(terraform|tfRepo)-[^/]*/::' file
services/history_book_test
services/history_book_test
or using any awk:
$ awk '{sub(".*/(terraform|tfRepo)-[^/]*/","")} 1' file
services/history_book_test
services/history_book_test
Regarding your attempt with sed sed 's|.*terraform.\([^/]*\)/.*|\1|' - if you're going to use a char other than / for the delimiters, don't use a char like | that's a regexp or backreference metachar as at best that obfuscates your code, pick some char that's always literal instead, e.g. :.

Replace chars after column X

Lets say my data looks like this
iqwertyuiop
and I want to replace all the letters i after column 3 with a Z.. so my output would look like this
iqwertyuZop
How can I do this with sed or awk?
It's not clear what you mean by "column" but maybe this is what you want using GNU awk for gensub():
$ echo iqwertyuiop | awk '{print substr($0,1,3) gensub(/i/,"Z","g",substr($0,4))}'
iqwertyuZop
Perl is handy for this: you can assign to a substring
$ echo "iiiiii" | perl -pe 'substr($_,3) =~ s/i/Z/g'
iiiZZZ
This would totally be ideal for the tr command, if only you didn't have the requirement that the first 3 characters remain untouched.
However, if you are okay using some bash tricks plus cut and paste, you can split the file into two parts and paste them back together afterwords:
paste -d'\0' <(cut -c-3 foo) <(cut -c4- foo | tr i Z)
The above uses paste to rejoin together the two parts of the file that get split with cut. The second section is piped through tr to translate i's to Z's.
(1) Here's a short-and-simple way to accomplish the task using GNU sed:
sed -r -e ':a;s/^(...)([^i]*)i/\1\2Z/g;ta'
This entails looping (t), and so would not be as efficient as non-looping approaches. The above can also be written using escaped parentheses instead of unescaped characters, and so there is no real need for the -r option. Other implementations of sed should (in principle) be up to the task as well, but your MMV.
(2) It's easy enough to use "old awk" as well:
awk '{s=substr($0,4);gsub(/i/,"Z",s); print substr($0,1,3) s}'
The most intuitive way would be to use awk:
awk 'BEGIN{FS="";OFS=FS}{for(i=4;i<=NF;i++){if($i=="i"){$i="Z"}}}1' file
FS="" splits the input string by characters into fields. We iterate trough character/field 4 to end and replace i by Z.
The final 1 evaluates to true and make awk print the modified input line.
With sed it looks not very intutive but still it is possible:
sed -r '
h # Backup the current line in hold buffer
s/.{3}// # Remove the first three characters
s/i/Z/g # Replace all i by Z
G # Append the contents of the hold buffer to the pattern buffer (this adds a newline between them)
s/(.*)\n(.{3}).*/\2\1/ # Remove that newline ^^^ and assemble the result
' file