help with grep - UNIX for Dummies Questions & Answers

mz043 · #1 05-24-2007

Hi.

I'm trying to grep a line that starts with a specific number from a file using a loop. The problem is:

grep -w $i filename (e.g. for i=1)

gives me back

line 1
line 10
line 11
...
and so forth. I only want 1 (and not 11, 12, 13. and so forth).

I need a loop that goes up to a large value, so I don't want to restrict the number of characters I'm searching for. I just want to match whole words and not letters within words. I thought the -w flag did that, but it's not. I also tried grep \<1\> to search for just "1" but i get no results back.

Thanks for your help!.

matrixmadhan · #2 05-24-2007

that should work,

Code:

>cat a
1
2
11
12
1

Code:

>i=1
>grep -w $i a
1
1

Could you please post sample of your input file ?

mz043 · #3 05-24-2007

hi,
thanks for the reply. the problem is because i'm using cat -n to number the lines in the file and then try to grep the line number. cat -n puts whitespace and i think that's where i 'm going wrong.

the format is

1 name
2 name
3 name
.
n name
thanks

matrixmadhan · #4 05-24-2007

pointer !

Code:

cat a
1 name
2 name
3 name
.
n name

Code:

i=1
sed -n "/$i/p" a | sed 's/ .*$//'

ghostdog74 · #5 05-25-2007

Code:

awk '/1/{ 
           for (i=1;i<=NF;i++){
               if ( $i == "1"){
                    print 
               }
           } }  ' "file"

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