Searching for a pattern that includes square brackets with awk-CodePudding

I'm trying to match a pattern with awk that contains square brackets. The pattern I am trying to match is:

[senderProcess:$PROCESS_ID:val:$ID]

where PROCESS_ID and ID are existing shell variables. I have tried defining a pattern variable in my awk statement:

awk -v pattern="[senderProcess:$PROCESS_ID:val:$ID]" '$0 ~ pattern && /GCLInbox run FINE/' $innerfile

When I run this, I get the following error:

awk: cmd. line:1: (FILENAME=logset1/teach-node-06.40490.log FNR=1) fatal: invalid regexp: Invalid range end: /[senderProcess:teach-node-06:40190:val:67]/

I took this as the awk shell interpreting the square brackets as regex special characters, so I tried escaping the brackets:

... pattern="\[senderProcess...$ID\]" ...

This gives the same error, in addition to the following two errors:

awk: warning: escape sequence `\[' treated as plain `['
awk: warning: escape sequence `\]' treated as plain `]'

I have also tried double escaping the brackets, with the same result.

I have tried using single quotes instead of double when declaring pattern, however I get the same errors, and regardless, my shell variables need to be expanded which would not happen here.

I just want to match the given pattern including its square brackets, whether that be by bypassing the regex special characters or some other way. Any help very much appreciated.

CodePudding user response：

You should make use of index function of awk try following code. Setting some test values to shell variables named ID and PROCESS_ID though its advised to have shell variable names in small case just going with your samples here. Then create a shell variable named var which is having concatenation of above mentioned 2 shell variables and then passing var to awk program.

ID="test1"
PROCESS_ID="test"
var="[senderProcess:${PROCESS_ID}:val:${ID}]"
awk -v pattern="$var" 'index($0,pattern) && /GCLInbox run FINE/' Input_file

CodePudding user response：

Creating the dynamic REGEX, you can include '[' and ']' within a list [...] and have each identified as the character instead of the start/end of a list.

I would try something similar to:

awk -v pattern="[[]senderProcess:$PROCESS_ID:val:$ID[]]" 'pattern && /GCLInbox run FINE/' $innerfile