(old)Puppy Linux Discussion Forum

Posted: **Wed 14 Feb 2018, 19:07**

Here's a tip I got from looking at the script 'mkplaylist' by Shinobar
available in ffconvert pet package....
http://www.murga-linux.com/puppy/viewto ... 27&t=54056

Explanation: I was having problems finding the correct field to cut
since the field was located at the end of a line.
Different operating systems were giving me different field locations.
However using 'rev' command makes the field number 1
and I can get the name of the mounted share folder consistently now.

Note that 'rev' command is used twice.

Code: Select all

# echo `df` | grep "/root/network/"|rev| cut -d " " -f1|rev
/root/network/GOLD-XP-2016-SharedDocs

_____________________________________________________________

Posted: **Wed 14 Feb 2018, 20:06**

don570 wrote:Here's a tip I got from looking at the script 'mkplaylist' by Shinobar
available in ffconvert pet package....
http://www.murga-linux.com/puppy/viewto ... 27&t=54056

Explanation: I was having problems finding the correct field to cut
since the field was located at the end of a line.
Different operating systems were giving me different field locations.
However using 'rev' command makes the field number 1
and I can get the name of the mounted share folder consistently now.

Note that 'rev' command is used twice.
Code: Select all
# echo `df` | grep "/root/network/"|rev| cut -d " " -f1|rev
/root/network/GOLD-XP-2016-SharedDocs
_____________________________________________________________

HI don570.

I probably would have used

Code: Select all

df | awk '{ print $NF }'

to get the last field.
But it's good to know there are several solutions for this.

BFN.

Posted: **Wed 14 Feb 2018, 21:19**

Thanks for info.
I'll check if it works in a script I wrote to mount and unmount a computer share in fatdogarm.

___________________________________

Reference site shows various methods including awk
https://stackoverflow.com/questions/227 ... -using-cut
_____________________________________

Posted: **Fri 16 Feb 2018, 20:10**

When I write scripts that are dialogs I always grab the script name to put as the dialog title. This way if user wants to rename the script, it displays the name they give it:

Code: Select all

MyName=$(echo $0 | rev | cut -d '/' -f1 | rev| tr '-' ' ')

'$0' holds the script name including full path. This clips off the path and leaves the name.

.

Posted: **Sat 17 Feb 2018, 16:07**

When I tested

Code: Select all

df | awk '{ print $NF }'

I discovered that it outputs a column of fields rather than the last field
The solution was to use the 'echo' command.

Code: Select all

echo `df` | awk '{ print $NF }'

Now I get the share folder

/root/network/GOLD-XP-2016-SharedDocs
__________________________________________

Posted: **Sat 17 Feb 2018, 17:25**

don570 wrote:When I tested
Code: Select all
df | awk '{ print $NF }'
I discovered that it outputs a column of fields rather than the last field
The solution was to use the 'echo' command.
Code: Select all
echo `df` | awk '{ print $NF }'
Now I get the share folder

/root/network/GOLD-XP-2016-SharedDocs
__________________________________________

You could also do this-

Code: Select all

 df | awk  '/GOLD-XP-2016-SharedDocs/ {print $NF}'

Look for the line containing "GOLD-XP-2016-SharedDocs" and then print the last field of that line.

Cheers,
s

Posted: **Sat 17 Feb 2018, 17:47**

don570 wrote:When I tested
Code: Select all
df | awk '{ print $NF }'
I discovered that it outputs a column of fields rather than the last field
The solution was to use the 'echo' command.
Code: Select all
echo `df` | awk '{ print $NF }'
Now I get the share folder

/root/network/GOLD-XP-2016-SharedDocs
__________________________________________

Strange.

My < df | awk > command does not need to be echoed.

Code: Select all

df | awk '/mnt/ { print $NF }'
/mnt/sda1
/initrd/mnt/tmpfs
/mnt/sda5
/mnt/sda6
/mnt/sda7
/mnt/sda8
/mnt/sdb2
/mnt/sdb5
/mnt/sdb6
/mnt/sdb7
/mnt/sdc3
/mnt/sdc5
/mnt/sdc6
/mnt/sdc7
/mnt/sdc8
/mnt/ram1

What "model" of awk do you have? I use mawk.

Posted: **Sat 17 Feb 2018, 18:27**

don570:

Use seaside's suggestion/explanation

Your awk is ok.
--
What you think works is a sort of a happenstance:
By echoing the output of df - you get a space-delimited list/line - the last field of that list "happens" to be the item you want.

Posted: **Sat 17 Feb 2018, 19:10**

some1 wrote: the last field of that list "happens" to be the item you want.

Samba shares always are always mounted last .
Is there any exceptions???

It's the folder that is mounted is what I need so i can unmount it
(with umount command)

echo `df` | awk '{ print $NF }' seems to work on my raspberry pi2.
http://www.murga-linux.com/puppy/viewto ... 353#983353
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Posted: **Sun 18 Feb 2018, 06:34**

don570 wrote:echo `df` | awk '{ print $NF }' seems to work on my raspberry pi2.

Maybe - if you are lucky. Removing another restriction (requiring df output to contain "/root/network/") makes it even less reliable than your original code.

Your original code should work fine, though not very efficiently, without the needless echo:

Code: Select all

df | grep "/root/network/"|rev| cut -d " " -f1|rev

If you don't remove echo the code will print the very last field of the def output, even if the field does not contain "/root/network/".

What's wrong with seaside's approach?

Code: Select all

df | awk  '/\/root\/network\// {print $NF}'

Using grep should even be simpler:

Code: Select all

df | grep -o '/root/network/.*'

Posted: **Tue 20 Feb 2018, 17:59**

Maybe - if you are lucky.

I checked with fatdogarm on a raspberry pi and I was wrong!!!

USB sticks that are inserted afterwards are placed at bottom of list.
So I removed the echo and used musher0 idea.

df then awk then grep

__________________________________________

df | grep -o '/root/network/.*'

Interesting! Never saw that option before.

________________________________________

Posted: **Tue 20 Feb 2018, 18:45**

don570 wrote:
Maybe - if you are lucky.
I checked with fatdogarm on a raspberry pi and I was wrong!!!

USB sticks that are inserted afterwards are placed at bottom of list.
So I removed the echo and used musher0 idea.

df then awk then grep
__________________________________________
df | grep -o '/root/network/.*'
Interesting! Never saw that option before.
________________________________________

Hi don.

Thanks for the vote of confidence.

When you say:
> df then awk then grep
you do not need that grep at the end, because awk has one built-in.

You could simply type:

Code: Select all

df | awk '$NF ~ /GOLD/ { print $NF }'

The < $NF ~ /GOLD/ > part means "The last field contains 'GOLD'."
In other words, you are telling awk:
"If there is a field that contains 'GOLD' in this df listing, print it."

(Which reminds me: I once met an old man who spent an entire afternoon telling
me tall tales about such a field in "Hope"

County, Yukon...)

TWYL.

(old)Puppy Linux Discussion Forum

Use rev command to get name of mounted share

Use rev command to get name of mounted share

Re: rev command use