sed command to replace a character at last

Shell Programming and Scripting
1

Hi All,
I have a file having one line only.
It is like
trapsess:inform|10.232.167.18|1|1|50|25|0|0|0|5|1|1|78|0037|

I want to replace the numbers in last two columns by As.

It should look like
trapsess:inform|10.232.167.18|1|1|50|25|0|0|0|5|1|1|AA|AAAA|

Please, suggest me any shell command for this.

Thanks in Advance.

2

One way,

awk -F\| '{$(NF-1)="AAAA";$(NF-2)="AA";print}' OFS=\| file
3 
 
perl -F"\|" -lane 'BEGIN{$,="|"}$F[-1]=~s/\d/A/g;$F[-2]=~s/\d/A/g;print @F'
4

awk command is not working, it is printing the my desired output, but not replacing the actual file.
I can redirect the output, but it may be a little more long in terms of line of code.

Thanks all for replying

5

Okies.. I misread the requirements.
Here is the updated one.

awk -F\| '{gsub(/[0-9]/,"A",$(NF-1));gsub(/[0-9]/,"A",$(NF-2));print}' OFS=\| file

EDIT: yeah. that wont edit the file.

6

If you want to edit the original file, use the below command

perl -i.bak -F"\|" -lane 'BEGIN{$,="|"}$F[-1]=~s/\d/A/g;$F[-2]=~s/\d/A/g;print @F'

input

7

Hi Anchal, I am still in same place. It is not replacing, just printing my desired requirement.
Thanks

8

try this ..

$ echo "inform|10.232.167.18|1|1|50|25|0|0|0|5|1|1|78|0037|" | sed 's,|[0-9][0-9]|[0-9][0-9][0-9][0-9]|,|AA|AAAA|,g'

inform|10.232.167.18|1|1|50|25|0|0|0|5|1|1|AA|AAAA|
9

Awk writes to the stdout.
If you don't want to create a temp file and must want to edit the original file. use perl (posted by getmmg).

10

or more simply

$ echo "inform|10.232.167.18|1|1|50|25|0|0|0|5|1|1|78|0037|" | sed 's:[^|]*|[^|]*|$:AA|AAAA|:'
inform|10.232.167.18|1|1|50|25|0|0|0|5|1|1|AA|AAAA|
11

borrowing from anchal_khare:

{ rm file; awk -F\| '{$(NF-1)="AAAA";$(NF-2)="AA";print}' OFS=\| file; } < file
12

I believe you meant to redirect AWK's stdout to "file". Otherwise, AWK will try to open ./file for reading, a pathname which does not exist after the rm.

As with any use of the unlink trick, should the last process holding open a file descriptor to the original "file" crash, you've lost the data (just a heads up for novices ;)).

Regards,
Alister

1 Like
13

ooops, fat fingers - good catch, thanks!

{ rm file; awk -F\| '{$(NF-1)="AAAA";$(NF-2)="AA";print}' OFS=\| > file; } < file