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Full Discussion: How to do I manipulate a variable in a do loop?
Top Forums Shell Programming and Scripting How to do I manipulate a variable in a do loop? Post 302935865 by RudiC on Thursday 19th of February 2015 04:21:30 PM
Old 02-19-2015
There's quite some methods to manipulate variables, be it within a loop or outside of it, but what you are doing above is not feasible. You are trying to execute the variable's contents like a command, but that doesn't exist: HOSTNAMEXXXX,168.192.100.150: command not found. You should have gotten this error msg as well. On top, counting chars is error prone - a host name's length changing will spoil your command. The eval (to be used judiciously) doesn't help here at all.
The straightforward way is to read the file according to its structure:
Code:
while IFS=, read host ip; do echo $ip $host; done < file
168.192.100.150 HOSTNAMEXXXX

ANother way would be to read one line into a variable and then use the shell's parameter expansion: Remove matching prefix pattern. (see e.g. man bash):
Code:
ip=${line#*,}
echo $ip
168.192.100.150

There's still other (powerful) options that can be applied to more complex problems.
This User Gave Thanks to RudiC For This Post:
ditnl555v
 

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LEARN ABOUT DEBIAN

oidentd_masq.conf

oidentd_masq.conf(5)						File Formats Manual					      oidentd_masq.conf(5)

NAME

       oidentd_masq.conf - oidentd IP masquerading/NAT configuration file.

DESCRIPTION

       If you are using IP masquerading or NAT, oidentd can optionally return a username for connections from other machines.  Support for this is
       specified by calling oidentd with the -m (or --masq) flag and by creating an /etc/oidentd_masq.conf file.

       oidentd can also forward requests for an IP masqueraded connection to the machine from which connection originates by way of the -f option.
       This  will  only  work if the host to which the connection is forwarded is running oidentd with the -P (proxy) flag, or if the host's ident
       daemon will return a valid reply regardless of the input supplied by and the address of the host requesting the info  (some  ident  daemons
       for windows do this, maybe others).

FORMAT

       <IP Address|Hostname>[/<Mask>] <Ident Response> <System Type>

       The  first  field  contains the IP address or the hostname of a machine that IP masquerades through the machine on which oidentd runs.  The
       mask parameter can be either a network mask or a mask in CIDR notation.	A mask of 24 is equivalent to  255.255.255.0,  a  mask	of  16	is
       equivalent to 255.255.0.0, etc.

       The second field specifies the reply that oidentd will return for lookups to the host matching the IP address specified in the first param-
       eter.

       The third field specifies the operating system the machine matching the first parameter is running.

EXAMPLES

       <Host>[/<Mask>]		<Ident Response>    <System Type>
       192.168.1.1		     someone		 UNIX
       192.168.1.2		     noone		 WINDOWS
       192.168.1.1/32		     user1		 UNIX
       192.168.1.0/24		     user3		 UNIX
       192.168.0.0/16		     user4		 UNIX
       somehost 		     user5		 UNIX
       192.168.1.0/255.255.255.0     user6		 UNIX

AUTHOR

       Ryan McCabe <ryan@numb.org>
       http://dev.ojnk.net

SEE ALSO

       oidentd(8) oidentd.conf(5)

version 2.0.8							    13 Jul 2003 					      oidentd_masq.conf(5)
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