How to combine two grep statements and display their results together?

Question

Suppose I do

   grep "MyVariable = False" FormA.frm

   ... result1

   grep "MyVariable = True"  FormA.frm

   ... result2

How to write the grep command so that I can say something like

   grep "MyVariable = False" OR "MyVariable = True" FormA.frm

You want to test whether a *line* contains `Var1 = False` AND `Var2 = True`? Or whether a *file* contains `Var1 = False` AND `Var2 = True`? Or something else? An example would help. — Mikel, Mar 28 '12 at 15:40

score 10 · Accepted Answer · answered Mar 28 '12 at 15:31

10

What you really want is "OR", not "AND". If "AND" is used, then logically, you'll get no lines (unless the line is something like "MyVariable = False...MyVariable = True".

Use "extended grep" and the OR operator (|).

grep -E 'MyVariable = False|MyVariable = True' FormA.frm

answered Mar 28 '12 at 15:31

Arcege

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Yes, you're right. I wanted OR but incorrectly specified AND. Thanks. – CodeBlue Mar 28 '12 at 15:40
Incidentally, I noticed this works only with an uppercase "E" and not a lowercase "e". So grep arguments are case sensitive I suppose. – CodeBlue Mar 28 '12 at 15:41
1

@CodeBlue: you should get used to this: almost everything is case sensitive in Unix – enzotib Mar 28 '12 at 16:00
Ok thanks @enzotib . I come from a Windows background. – CodeBlue Mar 28 '12 at 16:03
It also works with `egrep` (which I use) instead of `grep -E` which is the more canonical. – Arcege Mar 28 '12 at 16:58

score 3 · Answer 2 · answered Mar 28 '12 at 15:29

3

You should use

grep "MyVariable = \(False\|True\)" FormA.frm

where the \| sequence mean an alternative, and the delimiters \( and \) are for grouping.

answered Mar 28 '12 at 15:29

enzotib

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Yup, this also works, although it is a bit confusing to me. Thanks. – CodeBlue Mar 28 '12 at 15:47

score 1 · Answer 3 · edited Mar 28 '12 at 15:34

1

You can simply do

grep -E "MyVariable = False|MyVariable = True" FormA.frm

edited Mar 28 '12 at 15:34

Kevin

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answered Mar 28 '12 at 15:30

Sachin Divekar

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Vince · Answer 4 · 2018-06-13T14:48:15.333

1

To answer in another way than what has already been said...

You can also specify several matches to grep, by specifying the -e option several times

% grep -e "MyVariable = True" -e "MyVariable = False" FormA.frm
 ... result1
 ... result2

edited Jun 13 '18 at 14:48

answered Jun 13 '18 at 14:28

Vince

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It would be nice if you would write your answer using the text from the question rather than making up your own example. – G-Man Says 'Reinstate Monica' Jun 13 '18 at 14:40

How to combine two grep statements and display their results together?

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