mjhjmtu

I have a csv file of IDs.

1
3
8

I have another file of information, not only for the IDs, but also others. If I want to extract the information only of the IDs, how to do it?

1 96 283 4
2 87 918 6
2 49 208 5
3 57 294 0
3 24 284 0
4 28 345 290
5 23 234 209
6 98 245 02
7 18 329 89
8 19 239 78
8 18 289 90
9 28 390 09
9 19 238 09
10 23 899 7

I want to make this file

1 96 283 4
3 57 294 0
3 24 284 0
8 19 239 78
8 18 289 90

If the files are space-delimited and have Unix-style line endings:

cat file1.txt | xargs -I '' -n 1 grep '^ ' file2.txt

If you can homogenize the first field in each file (eg by adding a leading '0'), you can use join(1):

f1:

01
03
08

f2:

01 96 283 4
02 87 918 6
02 49 208 5
03 57 294 0
03 24 284 0
04 28 345 290
05 23 234 209
06 98 245 02
07 18 329 89
08 19 239 78
08 18 289 90
09 28 390 09
09 19 238 09
10 23 899 7

Then:

$ join f f2
01 96 283 4
03 57 294 0
03 24 284 0
08 19 239 78
08 18 289 90

I would use awk:

awk 'NR==FNRa[$0]++;nexta[$1]' file1 file2

where your IDs are in file1 and the rest in file2. The output:

1 96 283 4
3 57 294 0
3 24 284 0
8 19 239 78
8 18 289 90

using Miller you could do in this way

mlr --implicit-csv-header --headerless-csv-output --ifs " " --csv join -j 1 -r 1 -f joinInputOne.csv joinInputTwo.csv

to obtain


1,96,283,4
3,57,294,0
3,24,284,0
8,19,239,78
8,18,289,90


joinInputOne.csv is


1
3
8


and

joinInputTwo.csv is


1 96 283 4
2 87 918 6
2 49 208 5
3 57 294 0
3 24 284 0
4 28 345 290
5 23 234 209
6 98 245 02
7 18 329 89
8 19 239 78
8 18 289 90
9 28 390 09
9 19 238 09
10 23 899 7