Question

3

How to use sed to substitute current date?

rated 0 times [ 3] [ 0] / answers: 1 / hits: 1853 / 2 Years ago, thu, november 25, 2021, 9:35:21

How do I use sed to substitute date by a word. I tried doing this:

tmp=`date +%d`

echo $tmp

if [ $tmp -lt 10 ]

then

        pat="d"

        echo $pat

else

        pat="dd"

        echo $pat

fi

cal | sed "s/$tmp/$pat/"

And the output is like so:

robin@robin-VirtualBox:~/lx$ bash p13.sh

27

dd

     April 2014       

Su Mo Tu We Th Fr Sa  

       1  2  3  4  5  

 6  7  8  9 10 11 12  

13 14 15 16 17 18 19  

20 21 22 23 24 25 26  

27 28 29 30

Edit:

I want the date 27 to change into dd, like in here:

     April 2014       

Su Mo Tu We Th Fr Sa  

       1  2  3  4  5  

 6  7  8  9 10 11 12  

13 14 15 16 17 18 19  

20 21 22 23 24 25 26  

dd 28 29 30

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

ainsbeave

Add To Favorites

Follow

Total Points: 280

Total Questions: 98

Total Answers: 105

Location: Faroe Islands

Member since Sat, Aug 20, 2022

2 Years ago

ainsbeave questions

1 Is it possible to to create new file that also let's us rename it immediately after creating it?

Fri, Nov 25, 22, 08:54, 1 Year ago

1 Error: libcrypto.so.1.1: could not open while try run WPS-Office on Ubuntu 22.04 (Jammy Jellyfish)

Fri, Jun 10, 22, 12:46, 2 Years ago

1 How to configure Tilix to start with 4 splitted terminals by default

Mon, Jul 4, 22, 03:10, 2 Years ago

1 Boot options not appearing after Esc and all F## keys held when powering up laptop

Wed, Apr 6, 22, 16:40, 2 Years ago

1 I need to change tablet OS to Ubuntu

Wed, Mar 22, 23, 23:31, 1 Year ago

View All

answered 2 Years ago tatoethin · Accepted Answer

TL;DR: Use -h when using cal

Why?

The cal command prints the current day with special characters ("highlighting"?). I found out this saving it to a file and using nano (not cat) to read it:

$ cal >> out

$ nano out

Now you will see the following:

     Abril 2014

do lu ma mi ju vi sá

       1  2  3  4  5

 6  7  8  9 10 11 12

13 14 15 16 17 18 19

20 21 22 23 24 25 26

_^H2_^H7 28 29 30

Beside Spanish (sorry) 27 is not with simple characters.

Now if you use -h this is solved:

$ cal -h >> out2

$ nano out2

Your output should be like this so you can parse it without problems:

     Abril 2014

do lu ma mi ju vi sá

       1  2  3  4  5

 6  7  8  9 10 11 12

13 14 15 16 17 18 19

20 21 22 23 24 25 26

27 28 29 30

Solution

In your script replace cal | sed "s/$tmp/$pat/" with cal -h | sed "s/$tmp/$pat/"

Source: http://netbsd.gw.com/cgi-bin/man-cgi?cal+1+NetBSD-current