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Detect blank spaces in a CSV file

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# 1  
Old 10-03-2016
Detect blank spaces in a CSV file
I'm monitoring a WLAN network to keep track of new SSIDs popping up. The SSIDs are stored along with the AP MAC address and a few other parameters in a CSV file. A typical line could look like this:

Code:
18:70:9f:e3:80:aa 10:11:15  MyNetwork  2437

Now, the problem is that some networks use SSIDs with blank spaces. Then it looks like this:

Code:
18:70:9f:e3:80:aa 10:11:15  My Wi-Fi Network  2437

Some SSIDs come with no displayed SSID at all (hidden). The post-processing of these files of course become a bit cumbersome as some of the lines have three columns, some four and some more (depending on how many words the SSID is built up from).

Does someone know a smart way of detecting the SSID string and remove the blank spaces? Each line ends with the channel number (2437 above) and I could of course re-order the position of the columns so that the SSID is placed in the last column.

As the result, I would for example want "My Wi-Fi Network" to be converted to "My_Wi-Fi_Network". Like this:

Code:
18:70:9f:e3:80:aa 10:11:15  My_Wi-Fi_Network  2437

Cheers & thanks!
Sam
# 2  
Old 10-03-2016
If it's not comma-separated, it's not CSV. You've got a flatfile.

Code:
awk '{ S=""; for(N=3; N<NF; N++) S=S "_" $N ; print $1, $2, substr(S,2), $NF }' inputfile

These 2 Users Gave Thanks to Corona688 For This Post:
blastit.fr Zooma
# 3  
Old 10-04-2016
Hello Zooma,

Could you please try following too and let us know if this helps.
Let's say following is Input_file.
Code:
18:70:9f:e3:80:aa 10:11:15  My Wi-Fi Network  2437
18:70:9f:e3:80:aa 10:11:15  MyNetwork  2437

Following is the code as follows then.
Code:
awk 'NF>4{for(i=3;i<=NF-1;i++){S=S?S"_"$i:$i};print $1,$2,S,$NF;S="";next} 1'  Input_file

Output will be as follows.
Code:
18:70:9f:e3:80:aa 10:11:15 My_Wi-Fi_Network 2437
18:70:9f:e3:80:aa 10:11:15  MyNetwork  2437

Thanks,
R. Singh
Last edited by RavinderSingh13; 10-04-2016 at 01:18 AM..
This User Gave Thanks to RavinderSingh13 For This Post:
Zooma
# 4  
Old 10-04-2016
With any POSIX conforming shell, you could also do this entirely in the shell:
Code:
#!/bin/ksh
while IFS= read -r line
do	printf 'Processing %s\n' "$line"
	set -- $line
	ip=$1
	tm=$2
	shift 2
	SSID=
	while [ $# -gt 1 ]
	do	SSID=${SSID}_$1
		shift
	done
	SSID=${SSID#_}
	printf '%s %s %s %s\n' "$ip" "$tm" "$SSID" "$1"
done < file.csv

which, if file.csv contains:
Code:
18:70:9f:e3:80:aa 10:11:15 MyNetwork 2437
18:70:9f:e3:80:aa 10:11:15 My Wi-Fi Network 2438
18:70:9f:e3:80:aa 10:11:15 2439

produces the output:
Code:
Processing 18:70:9f:e3:80:aa 10:11:15 MyNetwork 2437
18:70:9f:e3:80:aa 10:11:15 MyNetwork 2437
Processing 18:70:9f:e3:80:aa 10:11:15 My Wi-Fi Network 2438
18:70:9f:e3:80:aa 10:11:15 My_Wi-Fi_Network 2438
Processing 18:70:9f:e3:80:aa 10:11:15 2439
18:70:9f:e3:80:aa 10:11:15  2439

These 2 Users Gave Thanks to Don Cragun For This Post:
wisecracker Zooma
# 5  
Old 10-04-2016
Corona688's suggestion (#2) did the trick! Thanks!

---------- Post updated at 08:55 AM ---------- Previous update was at 08:46 AM ----------

I also tried Dons and RavinderSinghs solutions, and they both seem to solve the problem. Thanks a lot for all help.

Cheers
Sam
Last edited by Zooma; 10-04-2016 at 09:47 AM.. Reason: Typo
This User Gave Thanks to Zooma For This Post:
Corona688
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