How to save particular lines from a dat file - sed

I have a file containing 10000 lines. I want to save data on particular lines. like line 205, 408 .. etc.
sed -n "205,408,611,814,1017,1220,1423,1626,1829,2032,2235,2438,2641,2844,3047,3250,3453,3656,3859,4062,4265,4468,4671,4874,5077,5280,5483,5686,5889,6092,6295p' evecs.dat > ext.dat
It shows an error :
sed: -e expression #1, char 8: unknown command: `,'

TO print only the 2nd and 4th line:
sed -n '2p;4p' file
Since you have many lines:
Prepare a file with all the line numbers, say here we want 2nd and 4th:
$ cat line
2
4
Prepare a string for the sed print command :
$ x=$(sed 's/$/p/' line | paste -sd";")
$ echo $x
2p;4p
Print those lines from the original file:
$ sed -n "$x" file

Related

Parse file and insert new line after each occurrence

On a Unix system I am trying to add a new line in a file using sed or perl but it seems I am missing something.
Supposing my file has multiple lines of texts, always ending like this {TNG:}}${1:F01.
I am trying to find a to way to add a new line after the }$, in this way {1 should always start on a new line.
I tried it by escaping $ sign using this:
perl -e '$/ = "\${"; while (<>) { s/\$}\{$/}\n{/; print; }' but it does not work.
Any ideas will be appreciated.
give this a try:
sed 's/{TNG:}}\$/&\n/' file > newfile
The sed will by default use BRE, that is, the {}s are literal characters. But we must escape the $.
kent$ cat f
{TNG:}}${1:F01.
kent$ sed 's/{TNG:}}\$/&\n/' f
{TNG:}}$
{1:F01.
With perl:
$ cat input.txt
line 1 {TNG:}}${1:F01
line 2 {TNG:}}${1:F01
$ perl -pe 's/TNG:\}\}\$\K/\n/' input.txt
line 1 {TNG:}}$
{1:F01
line 2 {TNG:}}$
{1:F01
(Read up on the -p and -n options in perlrun and use them instead of trying to do what they do in a one-liner yourself)

How to delete line with specific line numbers and save deleted and the rest?

test.txt contains:
this is a line
another line
one more line
For example, this can remove 1-2 lines, and save the rest into the rest.txt
sed -e '1,2d' test.txt > rest.txt
But the original file remains intact. Then how to get the remaining lines from the file? In this example, I want to remove the first 2 lines, save them into a file 'deleted.txt', and save the 3rd line into 'rest.txt'.
With GNU sed:
seq 1 5 | sed -e '1,2w deleted.txt' -e '1,2d' > rest.txt
w filename: Write the current pattern space to filename.
awk 'NR<=2{print $0 > "deleted.txt"}NR>2{print $0 > "rest.txt"}' test.txt
For lines(here NR) <= 2 redirect the output to deleted.
For lines(here NR) > 2 redirect the output to rest.txt.

sed: get a line number with regex and insert text at that line

I want to get the first line of a file that is not commented out with an hash, then append a line of text just after that line just before that line.
I managed to get the number of the line:
sed -n '/^\s*#/!{=;q}' file // prints 2
and also to insert text (specifying the line manually):
sed '2 a extralinecontent' file
I can't get them working together as a one liner or in a batch.
I tried command substitution (with $(command) and also with backticks) but I get an error from bash:
sed '$(sed -n '/^\s*#/!{=;q}' file) a extralinecontent' file
-bash: !{=: event not found
and also tried many other combinations, but no luck.
I'm using gnu-sed (via brew) on macOS.
This might work for you (GNU sed):
sed -e '/^\s*#/b;a extra line content' -e ':a;n;ba' file
Bail out of any lines beginning with a comment at the beginning of the file, append an extra line following the first line that is not a comment and keep fetching/printing all the remaining lines of the file.
Here's a way to do it with GNU sed without reading the file twice
$ cat ip.txt
#comment
foo baz good
123 456 7889
$ sed -e '0,/^\s*[^#[:space:]]/ {// a XYZ' -e '}' ip.txt
#comment
foo baz good
XYZ
123 456 7889
GNU sed allows first address to be 0 if the other address is regex, that way this will work even if first line matches the condition
/^\s*[^#[:space:]]/ as sed doesn't support possessive quantifier, need to ensure that the first character being matched by the character class isn't either a # or a whitespace character
// is a handy shortcut to repeat the last regex
a XYZ your required line to be appended (note that your question mentiones insert, so if you want that, use i instead of a)

Replace specific line numbers using 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

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