display which line returns specific output

Linux and Unix-Like UNIX and Linux Applications
1

Hi,
I'm trying to figure out a way to find which line in my file.txt with IP addresses:

192.168.0.1
192.178.0.2
etc...

returns specific result when I execute command affecting all lines.
For example when I run:

for line in `cat file.txt`;
do
snmpget $line
done

it displays the results from all lines but I cant tell which line returns which result. Any help on this?

2

Try:

for line in `cat file.txt`;
do
  echo "Line: $line"
  snmpget $line
  echo
done
3

What about adding an echo "This is the line $line"

for line in `cat file.txt`;
do
echo "This is the line $line"
snmpget $line
echo "-------------------------"
done

PS:- Oops, I think Bartus and I posted right around the same time :).

4

You get a useless use of cat award with useless use of backticks on the side. There's almost never a good reason to do this when the shell has a faster, simpler builtin without the unpredictable side-effects(data gets silently ignored, or program dies with 'too many arguments', or spaces cause the line to split early, etc, etc, etc)

while read LINE
do
...
done < filename
5

Great guys! It works just right!

If it's not too much to ask - is there a way to output the result on the same line:
not like
192.168.0.1
"result from command"

but as 192.168.0.1 "result of command"

Thanks again for your help!

6

Use printf instead of echo

while read line
do
  printf $line
  snmpget $line
done < file.txt

--ahamed