Replace specific line numbers using sed - sed

I use below to replace text on line numbers 29 to 32:
sed -i '29,32 s/^ *#//' file
How can I further add line numbers i.e. line 35 to 38, line 43 & line 45 in above command?

With GNU sed. m is here a label.
sed -i '29,32bm;35,38bm;43bm;45bm;b;:m;s/^ *#//' file
From man sed:
b label: Branch to label; if label is omitted, branch to end of script.
: label: Label for b and t commands.

This might work for you (GNU sed):
cat <<\! | sed 's:$:s/^ *#//:' | sed -f - -i file
29,32
35,38
43,45
!
Create a here-document with the line ranges you desire and pass these to a sed script that creates another sed script which is run against the desired file.
The here-document could be replaced by a file:
sed 's:$:s/^ *#//:' lineRangeFile | sed -f - -i file

Related

combine sed d and sed a scripts to a single script

file xz.txt
123
456
789
I want to merge
sed -i '1d' xz.txt
sed -i '1a abc' xz.txt
I tried
sed -i -e '1d' -e '1a abc' xz.txt
expect to get
456
abc
789
but I got
456
789
sed (GNU sed) 4.7
but it doesn't work, any help?
Sed goes line by line, first command 1d - deleted 1st line, 1st line is gone, there is no more 1st line, that is why second command 1a abc didn't work. Here is how it should be:
$ sed '1d; 2a abc' f
456
abc
789
What is going on is that the delete statement automatically ends the processing sequence:
[1addr]a\
text Write text to standard output as described previously (yes there is a new-line here)
[2addr]d: Delete the pattern space and start the next cycle
Source: Posix)
As the a command does not modify the pattern space but just writes to stdout, you can simply do
[POSIX]$ sed -e '1a\
abc' -e '1d'
[GNU]$ sed -e '1a abc' -e '1d'
However, the easiest is just to use the replace command c:
[POSIX]$ sed -e '1c\
abc'
[GNU]$ sed -e '1c abc`
Note: The reason the commands a and c write directly to the output and not to the pattern space is most likely that it would mess up the address ranging using line-numbers.

sed select line and substitute string in one command

I want to print only line 49 and substitute ',' for tab (ideally with sed).
sed -n '49p' file.txt | sed 's/,/\t/g'
How do I do it in one command without piping?
sed -n '49p; s/,/\t/g' would not work, neither sed '49p; s/,/\t/g'.
Thank you!
49 is an address and p and s// are commands. You can prefix any command by an address. So, instead of using just p on line 49 use s/// first:
sed -n '49s/,/\t/gp' file
Note that in this case p is just a flag for s/// and not the actual p command. For the more general case of arbitrary commands, you can repeat the address for each command 49s/,/\t/g; 49p or group the command behind one address 49 { s/,/\t/g; p }.
As pointed out in the comments you can speed up the command by exiting sed after line 49, so that the rest of the file isn't processed anymore (similar to head -n 49 | sed):
sed -n '49 { s/,/\t/gp; q }' file
You could delete any line that is not line 49, which ignores the rest of the sed commands except on line 49:
sed '49!d;s/,/\t/g' file.txt
If you want to do it with awk, you can use
awk 'NR==49{gsub(/,/,"\t");print;exit}' file
The NR==49 will check if Line 49 is being processed, and if yes, gsub(/,/,"\t") will replace each comma with a tab char in the line, and print will show it and exit will stop awk from processing further lines.
This might work for you (GNU sed):
sed '49!d;y/,/\t/;q' file
If it is not line 49, delete it.
If it is line 49, translate commas to tabs and quit.

Better way to fix mocha lcov output using sed

Due to the know prob of mocha-lcov-mocha breaking file paths, I need to fix the current output paths that looks like this:
SF:Vis/test-Guid.coffee
SF:Vis/Guid.coffee
SF:Vis/test-Vis-Edge.coffee
SF:Vis/Vis-Edge.coffee
into
SF:test/Vis/test-Guid.coffee
SF:src/Vis/Guid.coffee
SF:test/Vis/test-Vis-Edge.coffee
SF:src/Vis/Vis-Edge.coffee
I'm not very good with sed, but I got it to work using:
mocha -R mocha-lcov-reporter _coverage/test --recursive | sed 's,SF:,SF:src/,' | sed s',SF.*test.*,SF:test//&,' | sed s',/SF:,,' | sed s',test/src,test,' | ./node_modules/coveralls/bin/coveralls.js
which is basically doing 4 sed commands in sequence
sed 's,SF:,SF:src/,'
sed s',SF.*test.*,SF:test//&,'
sed s',/SF:,,'
sed s',test/src,test,'
my question is if there is a way to do with this one sed command, or use another osx/linux command line tool
Initially put "src/" after every ":" and then if "test" is found on the line replace "src" with "test":
$ sed 's,:,:src/,;/test/s,src,test,' file
SF:test/Vis/test-Guid.coffee
SF:src/Vis/Guid.coffee
SF:test/Vis/test-Vis-Edge.coffee
SF:src/Vis/Vis-Edge.coffee
You could put all the sed commands in a file, one line per command, and just use "sed -e script". But if you just want it on a single command-line, separate with semicolons. This works for me:
sed 's,SF:,SF:src/,;s,SF.*test.*,SF:test//&,;s,SF:,,;s,test/src/,test,'
sed command
sed '\#test#!{s#SF:Vis/#SF:src/Vis/#g};\#SF:Vis/test#{s#SF:Vis/test#SF:test/Vis/test#g};' my_file
Here is an awk version:
awk -F: '/SF/ {$0=$1FS (/test/?"test/":"src/")$2}1' file
SF:test/Vis/test-Guid.coffee
SF:src/Vis/Guid.coffee
SF:test/Vis/test-Vis-Edge.coffee
SF:src/Vis/Vis-Edge.coffee
How it works:
awk -F: ' # Set field separator to ":"
/SF/{ # Does line start with "SF"?
$0=$1FS (/test/?"test/":"src/")$2 # Recreat String by adding "test" if line contains "test", else "src"
}
1 # Print all lines
' file # read the file

Sed or awk: how to call line addresses from separate file?

I have 'file1' with (say) 100 lines. I want to use sed or awk to print lines 23, 71 and 84 (for example) to 'file2'. Those 3 line numbers are in a separate file, 'list', with each number on a separate line.
When I use either of these commands, only line 84 gets printed:
for i in $(cat list); do sed -n "${i}p" file1 > file2; done
for i in $(cat list); do awk 'NR==x {print}' x=$i file1 > file2; done
Can a for loop be used in this way to supply line addresses to sed or awk?
This might work for you (GNU sed):
sed 's/.*/&p/' list | sed -nf - file1 >file2
Use list to build a sed script.
You need to do > after the loop in order to capture everything. Since you are using it inside the loop, the file gets overwritten. Inside the loop you need to do >>.
Good practice is to or use > outside the loop so the file is not open for writing during every loop iteration.
However, you can do everything in awk without for loop.
awk 'NR==FNR{a[$1]++;next}FNR in a' list file1 > file2
You have to >>(append to the file) . But you are overwriting the file. That is why, You are always getting 84 line only in the file2.
Try use,
for i in $(cat list); do sed -n "${i}p" file1 >> file2; done
With sed:
sed -n $(sed -e 's/^/-e /' -e 's/$/p/' list) input
given the example input, the inner command create a string like this: `
-e 23p
-e 71p
-e 84p
so the outer sed then prints out given lines
You can avoid running sed/awk in a for/while loop altgether:
# store all lines numbers in a variable using pipe
lines=$(echo $(<list) | sed 's/ /|/g')
# print lines of specified line numbers and store output
awk -v lineS="^($lines)$" 'NR ~ lineS' file1 > out

GNU sed: global substitution failing

I have a file called test.csv with the following content:
T1,T2,T3,T4
10,2,3,17
10,2,5,14
10,2,2,16
15,1,17,15
12,1,9,25
I want to replace all the values 17 on the fourth column by 25. So I tried the command:
cat test.csv | sed -r 's/(([1-9]+,){3})17/\125/g'
T1,T2,T3,T4
10,2,3,17
10,2,5,14
10,2,2,16
15,1,17,15
12,1,9,25
As you can see, only the last row was modified, but not the second.
However, if I do: cat test.csv | sed -r "s/([0-9]+,[0-9]+,[0-9]+,)17/\125/" I have the output I want. Why is that?
The reason your sed line didn't work is:
if you check your sed line carefully,
cat test.csv | sed -r 's/(([1-9]+,){3})17/\125/g' (your sed line)
you had [1-9] not [0-9], fix that and try again, it should work for you.
also the cat file is not required. you can do sed '...' file