Eliminating whitespaces during reading of a field.

videsh77 · #1 (**permalink**) 12-13-2004

I am reading a field from a file. This field have trailing whitespaces.
Does anyone knows, how to get rid of these whitespaces, at the time of reading?

I know sed command as follows which removes whitespaces on a row -
sed 's/[ \t]*$//' rows

zazzybob · #2 (**permalink**) 12-13-2004

I normally use awk.

For example, say we had a tab delimtied file where fields sometimes have trailing spaces (i.e. between the data and the tab/newline), such as

Code:

field1          field2          field3
field1-a        field2-a        field3-a

Looking at this with od, we can see the spaces

Code:

$ od -ta datafile
0000000   f   i   e   l   d   1  sp  sp  ht   f   i   e   l   d   2  sp
0000020  sp  sp  ht   f   i   e   l   d   3  sp  sp  sp  nl   f   i   e
0000040   l   d   1   -   a  sp  sp  sp  ht   f   i   e   l   d   2   -
0000060   a  sp  sp  sp  sp  ht   f   i   e   l   d   3   -   a  sp  sp
0000100  sp  sp  sp  sp  sp  nl  nl
0000107

Awk will grab the tab-delimited fields and discard the spaces, i.e. to print just the first field...

Code:

awk '{print $1}' datafile

Piping the output through od, we can see that the trailing spaces are gone

Code:

$ awk '{print $1}' datafile | od -ta
0000000   f   i   e   l   d   1  nl   f   i   e   l   d   1   -   a  nl
0000020  nl
0000021

If you've got trailing tabs, then awk should take care of these too (depending on the format of the file).

If this isn't what you want - post a sample of the input file.

Cheers
ZB

videsh77 · #3 (**permalink**) 12-13-2004

Zazzybob,

The solution you have suggested removes spaces after reading the field from the file.
I want solution something like, at the time of reading this field, there
shouldnt be any trailing spaces.

Let me make my problem statement clear by an illustration-

Suppose I have a following file "tmpFile" :

'1111,aaa '
'2222,bbbb '

excluding single quotes, those I have shown in order to signify the presence of
trailing spaces at the end of the record.

Now if I run following command,
awk -F"," '{printf("%s:%s\n", $1,$2) }' tmpFile

$2 field is read as-
'aaa '
'bbbb '

Actually at the time of reading, I would like to read as -
'aaa'
'bbbb'

I dont want to execute new command sed to strip off
the trailing whitespaces, which I achieve with the following command -
awk -F"," '{printf("%s:%s\n", $1,$2) }' tmpFile | sed 's/[ \t]*$//'

Can we strip-off whitespaces at the time of reading?

zazzybob · #4 (**permalink**) 12-13-2004

You could do something like this (modify it to suit your needs)

Code:

awk -F',' '{gsub(/[\t ]*$/,"",$2);print $2}' datafile

Cheers
ZB

videsh77 · #5 (**permalink**) 12-13-2004

Thanx a ton zazzybob,
It helps!

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