Input file:
$ cat ids.txt
00009
01902
34390
00190
00001
Required: Remove the leading zero's from each of the lines in the above file.
Using sed:
$ sed 's/^[0]*//' ids.txt
Output:
9
1902
34390
190
1
So in vi ex mode, the command for the same will be:
:1,$ s/^[0]*//
Other alternatives:
$ awk '{printf "%d\n",$0}' ids.txt
$ awk '{print $1 + 0}' ids.txt
$ cat ids.txt | bc
Using bash parameter substitution:
$ shopt | grep extglob
extglob off
# Set this option on
$ shopt -s extglob
$ i=000100
$ echo ${i##+(0)}
100
extglob shell option in bash:
If set, the extended pattern matching features are enabled
Now if you are thinking how we can add zero's at beginning of a bash variable, here is the way using printf:
$ printf "%010d\n" 00005
0000000005
You might look at this post which shows how we can make some numbers equal width by padding the number with leading zeroes.
Some related posts:
Replace leading zero's with blank using sed
Remove white space in vi editor
Posts
15 comments:
I appreciate all your posts. It really has helped educate me in scripting, especially with awk/sed.
@Nate, thanks.
Hai Jadu,
How i can replace the "," by the "|" in this text.
ab,cd,ef,gh
gh,jg,gj,yu
To
ab|cd|ef|gh
gh|jg|gj|yu
Many thanxs Jadu
Hai jadu,
How to convert this text.
ab,cd,ef,gh
ij,kl,mn,op
to become
ab|cd|ef|gh
ij|kl|mn|op
Thanxs Jadu
@Taufik,
This should be a sed replacement like this:
sed 's/,/|/g' file > file.tmp
sed file.tmp file
or if you have -i support on sed
sed -i 's/,/|/g' file
Also you can have a look on this post:
http://unstableme.blogspot.com/2008/01/awk-change-field-separator-add-line.html
Hope this helps. Keep in touch.
It is not necessary to enclose zero inside square brackets.
sed 's/^[0]*//' ids.txt
can be
sed 's/^0*//' ids.txt
@Mahesh, true. Thanks
Hi all, sorry I dont if this is the right place to put my query. I have a file with lots of characters, and I want to remove all the characters after the 4th character in all lines, e.g.
1234456
7654328
1209873
so remove characters to become
1234
7654
1209
please can you help?
FR
@Retagi,
Something like this ?
$ sed 's/^\(....\).*$/\1/' file.txt
o/p:
1234
7654
1209
or
$ awk 'BEGIN {FS=OFS=""} {print $1,$2,$3,$4}' file.txt
Situation:
Delete all directories, except a directory.
Tip:
# mkdir a b c
# shopt -s extglob
# rm -rf !(c)
(This will remove directories a and b, but keeps c)
@Ana, sorry could not reply to you last day. Assuming you want to split the master file into subfiles starting with "DESCRIPTION", here is a solution using awk:
$ awk '/^DESCRIPTION/{close("sub_"f);f++}{print $0 > "sub_"f}' file.txt
Please let me know if your requirement was different. Thanks for your comment.
how to remove the 0 in front of the comma ..
example:
0.4
but I got out just .4
how to remove it 0
@Agung Kurniawan Faisol , do you mean how to get .4 from 0.4 ? Please confirm. Thanks.
@Retagi,
You can use 'cut' to extract substrings...
per your example...
cut -c 1-4 file.txt
> Required: Remove the leading
> zero's from each of the lines...
> sed 's/^[0]*//'
Actually this will null the line
which has an entry like 000000
i.e., all zeros. Then when you try to pipe the result, it may/may not cause errors...
This would mitigate the issue
sed -e 's/^[0][0]*\(.\)/\1/'
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