CODEWITHSUNDEEP
awksedgrep
user2182606
user2182606

Reputation: 61

Unix command (grep, sed or awk): output as input and search a file

I would very much appreciate if someone can help me.

I would like to perform this task using some commands, either grep, sed, or awk (or something else). I have two in-files.

File 1 

0  
1  
4

File 2 

S   0   1832    *   0   *   *   *  
S   1   1801    *   0   *   *   *  
H   1   1298    99.2    +   0   0   301M10I997M493I  
S   2   1791    *   0   *   *   *  
S   3   1720    *   0   *   *   *  
S   4   1693    *   0   *   *   *  
S   11  1693    *   0   *   *   *

The output what I want is 

S   0   1832    *   0   *   *   *  
S   1   1801    *   0   *   *   *  
H   1   1298    99.2    +   0   0   301M10I997M493I  
S   4   1693    *   0   *   *   *

So, if the second column of file2 matched with file1 lines, extract to the output. This is what I want to do.

Upvotes: 1

Views: 440

Answers (1)

JFS31
JFS31

Reputation: 518

Here is the classic solution in awk:

awk 'FNR==NR{ a[$1]; next }$2 in a{ print $0 }' file1 file2

Output:

S   0   1832    *   0   *   *   *  
S   1   1801    *   0   *   *   *  
H   1   1298    99.2    +   0   0   301M10I997M493I  
S   4   1693    *   0   *   *   *

The first part of the command is only executed on file1 due to the pattern FNR==NR which is only true for file1. It uses $1 as an index for the array a. The next command checks if $2 of file2 is in as an index in the array. $2 in file2 the desired match. And the last command prints the whole matching line of file2.

Upvotes: 2

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