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awk to delete word when found

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# 1  
Old 08-15-2012
awk to delete word when found
i'm trying to use the following awk statement to delete every host name it finds in the hostlist file from the configuration file (conf.txt).

Code:
awk 'NR==FNR {a=(a?a"|":"")$0; next}; match ($0,a) {print $0 RS}' hostlist RS="}" conf.txt

i think something like this will be necessary but i dont know how to add it to the above statement:

Code:
sub("$a", "")

# 2  
Old 08-16-2012
please provide the sample input data and required output
# 3  
Old 08-16-2012
Looks like the continuation of your previous thread (see there for sample data); what does not work with above statement? It sucks in the hostlist to compose a large regex, then reads your conf.txt file one configuration entry at a time. If the hostname is NOT found in the regex, the entry is printed. In your above citation, the ! sign in front of the match is missing to EXclude the respective host.
sub("$a", "") definitely is not needed.

Btw, do you want to delete just the hostname or the entire conf entry for that hostname?
Last edited by RudiC; 08-16-2012 at 04:14 AM..
This User Gave Thanks to RudiC For This Post:
SkySmart
# 4  
Old 08-16-2012
Quote:
Originally Posted by RudiC
Looks like the continuation of your previous thread (see there for sample data); what does not work with above statement? It sucks in the hostlist to compose a large regex, then reads your conf.txt file one configuration entry at a time. If the hostname is NOT found in the regex, the entry is printed. In your above citation, the ! sign in front of the match is missing to EXclude the respective host.
sub("$a", "") definitely is not needed.

Btw, do you want to delete just the hostname or the entire conf entry for that hostname?
thank you so much for correlating this thread to the other thread.

i want to delete just the host name. what's not working is that, this time, i'm running the awk command against a different configuration file. the other configuration file in the other thread was the configuration specifically for hosts.

now, the configuration file i'm working on is the configuration file for the hostgroup(s) of which the host names in the list belong to.

below is an output of this hostgroup configuration file:

Code:
define hostgroup {
      alias		Virtual Machines Primary Site
      hostgroup_name	virt-machines-primary
      members           relay-nasty-01.net,relay-nasty-02.net,relay-nasty-03.net
      use		generic-hostgroup
}


define hostgroup {
      alias		Virtual Machines Secondary Site
      hostgroup_name	virt-machines-secondary
      members           relay-nasty-04.net,relay-nasty-05.net,relay-nasty-06.net
      use		generic-hostgroup
}

so when i run the awk command against this configuration file, if it finds, for example, relay-nasty-01.net in the hostgroup called virt-machines-primary, i want it to remove that host name from that group and leave the remaining host names in that group intact UNLESS they're also in the list of host names that the awk is looking to remove.
# 5  
Old 08-16-2012
You can't use above command as it will delete the entire conf entry. Try this:
Code:
awk 'NR==FNR {a=(a?a"|":"")$0; next}; {gsub(a,""); gsub(" ,+"," "); gsub(",+$","")} 1' host_file conf_file

It loads all host names to compose a regex, and then eliminates any member of the regex from your file. Residual leading and trailing commas have to be eliminated as well.
This User Gave Thanks to RudiC For This Post:
SkySmart
# 6  
Old 08-16-2012
Quote:
Originally Posted by RudiC
You can't use above command as it will delete the entire conf entry. Try this:
Code:
awk 'NR==FNR {a=(a?a"|":"")$0; next}; {gsub(a,""); gsub(" ,+"," "); gsub(",+$","")} 1' host_file conf_file

It loads all host names to compose a regex, and then eliminates any member of the regex from your file. Residual leading and trailing commas have to be eliminated as well.
this works wonderfully.

i think i need a simple modification. after it removes the host name, there is a ",," left in the place of teh host name. this usually happens if the host name is not first in the list.

example:

conf file

Code:
define hostgroup {
      alias		Virtual Machines Primary Site
      hostgroup_name	virt-machines-primary
      members           relay-nasty-01.net,relay-nasty-02.net,relay-nasty-03.net,relay-nasty-03b.net
      use		generic-hostgroup
}

if i included only "relay-nasty-02.net" in the host list, and i ran the awk command, what results is this:

Code:
define hostgroup {
      alias		Virtual Machines Primary Site
      hostgroup_name	virt-machines-primary
      members           relay-nasty-01.net,,relay-nasty-03.net,relay-nasty-03b.net
      use		generic-hostgroup
}

if i were to add relay-nasty-03.net to the list of hosts to remove, i get this:

Code:
define hostgroup {
      alias		Virtual Machines Primary Site
      hostgroup_name	virt-machines-primary
      members           relay-nasty-01.net,,,relay-nasty-03b.net
      use		generic-hostgroup
}

Last edited by SkySmart; 08-16-2012 at 07:56 AM..
# 7  
Old 08-16-2012
Rats! I knew I forgot sth. Put a
Code:
;gsub(",+",",")

after the last gsub. Sorry!
This User Gave Thanks to RudiC For This Post:
SkySmart
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