Check if string starts with substring or not using bash – Code Example

In this article we will provide you bash script code example to check if substring is present at the start of the string. This code won’t check any other occurrences of the substring.

Code Example –

1. Check if substring is at the start –

#!/bin/bash

var="This is a string"

if [[ $var == Th* ]]; then
    printf '%s\n' "var starts with sub_string."
fi

# Output:
# var starts with sub_string.

2. Check if substring is not at the start –

#!/bin/bash

var="This is a string"

if [[ $var != is* ]]; then
    printf '%s\n' "var does not start with sub_string."
fi

# Output:
# var does not start with sub_string.

3. Check if substring is at the start of array –

#!/bin/bash

arr=("This" "is a" "string")

if [[ ${arr[*]} == Th* ]]; then
    printf '%s\n' "sub_string is in start of array."
fi

# Output:
# sub_string is in start of array.

4. Check if substring is not at the start of the array –

#!/bin/bash

arr=("This" "is a" "string")

if [[ ${arr[*]} != is* ]]; then
    printf '%s\n' "sub_string is not in start of array."
fi

# Output:
# sub_string is not in start of array.

Inspired from Dylan Araps

Live Demo

Open Live Demo