Add/edit line text in file without open editor (linux command) [duplicate]

Question

I know how to add new text to a file, but how can I edit it?

Example: adding hello_world = 1 to test.txt using the following command:

echo "hello_world = 1" >> test.txt

But how can I change 1 to 0 or something else?

What is your mean by without open editor i.e. you don't want use also useful CLI text editor like: vi or nano as well as GUI like: gedit — Pandya, Jul 2, 2014 at 12:08
because I want to make a script for my android, I know android use linux kernel and has some linux command. And my script working perfectly — Marco98T, Jul 5, 2014 at 9:28

Radu Rădeanu · Accepted Answer · 2014-07-02 11:28:27Z

35

Using sed:

sed -i 's/1/0/g' test.txt

In general:

sed -i 's/oldstring/newstring/g' filename

See man sed for more info.

answered Jul 2, 2014 at 11:28

Radu Rădeanu

170k49 gold badges328 silver badges402 bronze badges

for single substitution, you don't even need a global flag.
– Avinash Raj
Jul 2, 2014 at 11:55
Downvote because answer is already exists here.
– c0rp
Jul 2, 2014 at 12:17
Why do you downvote the correct answer then, cOrp, and not the duplicate question?
– foo
Sep 3, 2020 at 14:19

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Avinash Raj · Accepted Answer · 2014-07-02 11:54:15Z

5

Through awk,

awk '{sub(/1/,"0")}1' infile > outfile

Example:

$ echo 'hello_world = 1' | awk '{sub(/1/,"0")}1'
hello_world = 0

answered Jul 2, 2014 at 11:54

Avinash Raj

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2 Answers 2