function returns string

Shell Programming and Scripting
1

Can I create a function to return non-interger value in shell script?

for example,
function getcommand ()
{
echo "read command"
read command
echo $command

}

command=$(getcommand)

I tried to do something as above. The statement echo "read command" does not show up.

Normally, how can we create a function to return something except an integer?

2 
#!/bin/ksh

concatenate_two_words()
{
    echo "$1""$2"
}

word1="hi"
word2="there"
both=$(concatenate_two_words "$word1" "$word2")
echo "$both"

To return a string echo "the string" as the last line of the function and then call the function as a subprocess
with either ` ` backtics or $ ( )

3

another alternative is to define a "global" variable

funct_ret_value=""

function getcommand ()
{
echo "read command"
read command
funct_ret_value=$command

}

getcommand
echo $funct_ret_value

4

When you call a function in ` ` or $( ), the child process is spawned. Am I right?
Therefore, the statement echo "read command" does not print out to the shell I am running the script. How can I print it out to the running shell if I use the function that is called in ` ` or $( ). The echo statement is in that function.

5

Why are you echo - ing and then reading a value inside of a function that runs as a subprocess?

  • The echo "read command" appears in the variable you are trying to receive in the calling process. It does not appear on the console.
6

Actually, it is nothing I want to do. I am starting to learn unix and I am trying many possible ways to make myself understood as much as possible. Therefore, this question came up when I compare a function in shell programming to other programming langauges.
Furthermore, the book I have been studying writes something about break:

while true
do
cmd=$(getcommand)
if [ "cmd" =quit ]
then
break
fi
done

See that made me think about how to write the getcommand function. So I put the echo-ing and read in a function and return a string.

Thanks for your answers anyway