Grep command

Shell Programming and Scripting
1 
grep -v '^[ ]*1'

explain what is the output of the command.

2

Hello dineshaila,

Following may help you in same.

cat Input_file
<a><b>Bee</b><c>Sea</c><d><e>Eeeh!</e></d></a>
   1dtessd  vufgugyug hgyugg

Then following command we ran as follows:

grep -v '^ *1'  Input_file

So output will be as follows.

<a><b>Bee</b><c>Sea</c><d><e>Eeeh!</e></d></a>

So basically -v option omits the line to print if pattern following it is matched like as above(It is not printing the second line because it starts with a space and then followed by digit 1 ), which actually satisfy the regex provided after -v option. You could read man page for grep too by doing man grep .

Thanks,
R. Singh

3

it is also not printing

echo "123"|grep -v '^[ ]*1'

if the pattern contains 1

4

As Ravinder already wrote -v omitts the printing of the matching lines. The * stands for any number of the former character (a blank), even none.

So it does not print this.

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