CODEWITHSUNDEEP
linuxbashvariablesstring
DAT BOI
DAT BOI

Reputation: 183

adding a number variable with a string

I'm asking the user to enter a number and if the number is greater than 2 then I like to add the string -n to that number. Here's my code:

read -p "Enter a number " result_sort
if [ $result_sort >2 ]; then

   result_sort = $result_sort + " -n"

fi

echo "$result_sort"

I'm getting the error: command not found

Upvotes: 0

Views: 84

Answers (4)

David C. Rankin
David C. Rankin

Reputation: 84652

The result can be accomplished simply by concatenating the string values of the variables:

read -p "Enter a number " result_sort

[ "$result_sort" > 2 ] && 
result_sort="${result_sort}-n"

echo "$result_sort"

brace protecting the variable can prevent ambiguity. Also using the arithmetic comparison given by anubhava can protect against users entering something other than numbers.

Upvotes: 1

anubhava
anubhava

Reputation: 786289

You can do this in BASH:

read -p "Enter a number " result_sort

((result_sort>2)) && result_sort+=" -n"

Upvotes: 1

chaos
chaos

Reputation: 9322

Your code should look like this:

read -p "Enter a number " result_sort
if [ $result_sort -gt 2 ]; then

   result_sort=$(echo "$result_sort -n")

fi

echo "$result_sort"

There were two mistakes:

  1. The test utility ([) you used doesn't accept < and > as greater and less. Those characters are redirection characters (see I/O Redirection) in the shell. Your statement in the if clause is always true, even if $result_sort is less than 2. You are writing the result of that command [ $result_sort ] to a file called 2.

  2. The concatenation of two strings cannot be done in your way.

Upvotes: 1

Jerin Joseph
Jerin Joseph

Reputation: 1097

try this

result_sort=`echo "${result_sort} -n"`

there should be no space between the result_sort and the "=" sign. In your case because of the space, it identifies result_sort as a command and tries to interpret it.

Upvotes: 1

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