Bash Loop Error

[Col8eral]

Try to run a simple loop script

#!/bin/sh
max=10
for (( i=2; i <= $max; ++i ))do
echo"$i"
done

but im getting "syntax error: bad for loop variable" when I run it. Wht am I doing wrong?
Thanks.

 

[Viktor Jaep]

Try to run a simple loop script

#!/bin/sh
max=10
for (( i=2; i <= $max; ++i ))do
echo"$i"
done

but im getting "syntax error: bad for loop variable" when I run it. Wht am I doing wrong?
Thanks.

Just a quick clarification. Our routers use POSIX, not Bash. (You can enable it if you so choose, but it gets more messy). POSIX shell has issues with advanced loops like this... you probably want to use something like this:

i=0
while [ $i -le 10 ]; do
    echo "$i"
    i=$(( i + 1 ))
done

 

[Col8eral]

Thank you. I tried that and got this error:
loop: line 7: syntax error: unexpected end of file (expecting "do")

 

[Viktor Jaep]

Thank you. I tried that and got this error:
loop: line 7: syntax error: unexpected end of file (expecting "do")

Make sure you set the environment at the top:

#!/bin/sh

i=0
while [ $i -le 10 ]; do
    echo "$i"
    i=$(( i + 1 ))
done

exit 0

This works for me:

 

[Col8eral]

thats strange. Its not working for me

Not sure what i'm doing wrong

 

[Viktor Jaep]

Not sure what i'm doing wrong

Are you copying and pasting from a Windows notepad window by chance? Or some other intermediary source? I have heard of instances where additional hidden characters will mess with the script. Try copying it from here, and pasting it directly within nano (right-click on your mouse while in nano)... then save it. See if that helps?

 

[ColinTaylor]

thats strange. Its not working for me
View attachment 64399

View attachment 64400

Not sure what i'm doing wrong

You previously omitted the first error message which gives the game away:

: not foundne 2:

You have created the file is DOS format instead of Unix format. Do the following and try running the script again:

dos2unix loop.sh

 

[Col8eral]

Hey, brilliant. Success . Thanks so much