Shell script conditions

Question

I am trying to get data from a text file using a shell script, by searching in some lines with more than one condition. For example in this file:

TX VIDEO ID 34 B 33 SIZE 672 SRC -1 DST 11 
TX CBR ID 35 B 35 SIZE 10 SRC -1 DST 11  
RX VOIP ID 0 B 0 SIZE 32 SRC -1 DST 3 D  
RX VOIP ID 8 B 8 SIZE 32 SRC -1 DST 5 D 
RX VOIP ID 20 B 20 SIZE 32 SRC -1 DST 8 D 
RX VIDEO ID 9 B 9 SIZE 1490 SRC -1 DST 5 D 
RX VIDEO ID 21 B 21 SIZE 1490 SRC -1 DST 8 D 
TX INF_BUF ID 37 B 10 SIZE 776 SRC 1 DST 5 T 
TX INF_BUF ID 39 B 22 SIZE 776 SRC 2 DST 8 T 

I have both the "RX VIDEO" and "TX VIDEO" lines. The first condition is, take data from all the "RX VIDEO" within the "DST 3 && DST 5" .

Answer 1

For more than one condition you can pipe greps output to another grep.

If you want to search a file for lines with AAA and BBB you can do:

grep 'AAA' file | grep 'BBB'

Or you can search it with regular expressions with only one grep:

grep -e 'AAA.*BBB' -e 'BBB.*AAA' file

If an expressions after any of the -e options are matched, you will get a result. That means that it acts like or .

Both examples will find lines like this ones:

AAABBB
AAA BBB
BBB AAA
BBBAAA
AAA-BBB
AAA---BBB
AAAA BBB
xAAAAAAA BBB AAAAA

and so on.

For your example it could be:

grep 'RX VIDEO' file | grep -e 'DST 3\>' -e 'DST 5\>'

Or:

grep 'RX VIDEO.*DST [35]\>' file

This will search for RX VIDEO together with DST 3 or DST 5 .

Edit: I added a word ending at the end of the expressions to surpress for example DST 37 beeing found. See Keith's comment.