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Cut adding $ and carriage return characters for MAC addresses

I have go a different way with this script, but very curious about this.

First the script I am using

Code:

cat mac.sh

#!/bin/bash -x





ifconfig eth0| grep HWaddr |tr -s ' ' |cut -d' ' -f5

MAC=`ifconfig eth0| grep HWaddr |tr -s ' ' |cut -d' ' -f5`



grep "$MAC"  maclist.txt|tr -s " " |cut -d" " -f1

HO1=`grep "$MAC"  maclist.txt |tr -s " " |cut -d" " -f1`

printf ${HO1}



grep "$MAC"  maclist.txt |tr -s " " |cut -d" " -f2

HO2=`grep "$MAC"  maclist.txt |tr -s " " |cut -d" " -f2`

printf ${HO2}



A='00:23:AE:69:C0:F2'

printf  ${A}



exit 0

And the output:

Code:

./mac.sh

+ ifconfig eth0

+ grep HWaddr

+ tr -s ' '

+ cut '-d ' -f5

00:23:AE:69:C0:F2

++ ifconfig eth0

++ grep HWaddr

++ tr -s ' '

++ cut '-d ' -f5

+ MAC=00:23:AE:69:C0:F2

+ grep 00:23:AE:69:C0:F2 maclist.txt

+ tr -s ' '

+ cut '-d ' -f1

om012274

++ grep 00:23:AE:69:C0:F2 maclist.txt

++ tr -s ' '

++ cut '-d ' -f1

+ HO1=om012274

+ printf om012274

om012274+ grep 00:23:AE:69:C0:F2 maclist.txt

+ tr -s ' '

+ cut '-d ' -f2

00:23:AE:69:C0:F2

++ grep 00:23:AE:69:C0:F2 maclist.txt

++ tr -s ' '

++ cut '-d ' -f2

+ HO2=$'00:23:AE:69:C0:F2\r'

+ printf $'00:23:AE:69:C0:F2\r'

+ A=00:23:AE:69:C0:F2

+ printf 00:23:AE:69:C0:F2

00:23:AE:69:C0:F2+ exit 0

The bit I am curious about is:
+ HO2=$'00:23:AE:69:C0:F2\r'

Anyone handy with text processing know about this?

Thanks

How did you create maclist.txt, on MSWin?
If so, you need to run dos2unix over it first to cvt MS line endings to Linux ones.

chrism01 oh of course. So obvious now.
Our Windows guy here created it, so that explains the carriage return.

But what about the prepended $ ?

Its like a regex start of line, but why would cut add that [or grep]?

It might be tr that's adding or such.

Code:

+ grep 00:23:AE:69:C0:F2 /mnt/altiris/maclist.txt

+ tr -s ' '

om012274 00:23:AE:69:C0:F2

++ grep 00:23:AE:69:C0:F2 /mnt/altiris/maclist.txt

++ tr -s ' '

' HO2='om012274 00:23:AE:69:C0:F2

+ printf om012274 $'00:23:AE:69:C0:F2\r'

om012274+ grep 00:23:AE:69:C0:F2 /mnt/altiris/maclist.txt

+ tr -s ' '

+ cut '-d ' -f2

00:23:AE:69:C0:F2

++ grep 00:23:AE:69:C0:F2 /mnt/altiris/maclist.txt

++ tr -s ' '

++ cut '-d ' -f2

+ HO2=$'00:23:AE:69:C0:F2\r'

+ printf $'00:23:AE:69:C0:F2\r'

+ A=00:23:AE:69:C0:F2

So I converted the line endings with vi and now the $ is gone too.

So for some reason DOS line endings added $ at the beginning of the MAC address but not the hostname which is at the start of the line.

Weird.