Looping through input variables and printing in shell script - linux

Question

Hi pls I'm new to shell scripting. I need to write a shell script that will ask for 2 parameters, one for startdate and another for number of days.
Then loop from start date to number of days and print each date.
E.g 16-09-2022 and 4 will print:
16-09-2022
17-09-2022
18-09-2022
19-09-2022
Tried this:
#! /bin/bash
echo "enter date"
read var1
echo "enter no of days"
read var2
for i in {0..$var2..1}
do
echo $i $var1
(here's where I'm trying to figure how to increment the dates)
done
Thanks

Answer 1

Try the following:
Save the script below in file, name it e.g. get-started-with-bash-by-example.sh and run it as follows:
bash get-started-with-bash-by-example.sh 2022-09-25 10
#!/bin/bash
# USAGE:
# ${SCRIPT_NAME} args
# arg1 - date (must be in format 'yyyy-mm-dd')
# arg2 - number of days to add
#
# EXAMPLES
# ${SCRIPT_NAME} 2022-09-25 10
for i in $(seq "$2")
do
date +%d-%m-%Y -d "$1 + $i day"
done
Or with user input:
#!/bin/bash
read -p "Enter start-date in 'yyyy-mm-dd' format: " startdate
read -p "Enter number of days to add: " nofdaystoadd
for i in $(seq "$nofdaystoadd")
do
date +%d-%m-%Y -d "$startdate + $i day"
done
OUTPUT:
26-09-2022
27-09-2022
28-09-2022
29-09-2022
30-09-2022
01-10-2022
02-10-2022
03-10-2022
04-10-2022
05-10-2022
I hope this example helps you to get started with bash.