Syntax error: word unexpected (expecting ")")

Shell Programming and Scripting
1

I have a very simple script that reads in the contents of a file (_open.txt) into an array "lyrics":

#!/bin/sh

# read in the text
lyrics=( `cat _open.txt` | tr '\n' ' ')

exit 0

It gives the following error message:
./lyrics.sh: 1: Syntax error: word unexpected (expecting ")")

I have also tried

lyrics=($(cat _open.txt))

as well as with and without quotes (single and double) around the filename.
but it yields the same error message. The path /bin/sh is correct. What is the error message really saying?

2

try this

#bash:
declare -a lyrics=$( <  _open.txt )
#ksh
set -A lyrics=$( <  _open.txt )

If you are using bash or ksh this will work. ksh limits the number of elements in an array to 1023. So _open.txt has to have less than 1024 "words" in it.

3

What shell is in /bin/sh?

Most shells do not have arrays, so you may have to change the shebang to one that does, perhaps "#!/bin/bash".

4

Thank you for your prompt response. What is the cause of the syntax error? By the way, the file contains a large word, ie a body of text without spaces, so is there a limit to what the array lyrics can hold in terms of maximum size of array element?

5

For bash there is no defined limit.

a=$( < war_and_peace.txt)

You could put a whole book into a bash variable or an array. You are limited by virtual memory on your machine.

ksh also allows variable to be really large as well, but limits the number of elements in an array.

6

Neither declaration is necessary. In either bash or ksh93, simply assigning it is enough:

lyrics=( $( tr '\n' ' ' <  _open.txt ) )

Note that you do not need tr; the shell will split the array on the characters in $IFS, which normally includes a space. So this is the same as the above:

lyrics=( $( <  _open.txt ) )

Ksh88 was limited to 1023 elements, but I don't think it accepted that syntax for assigning a number of elements to an array.

Ksh used to be limited to 4096 elements in an array, but versions for the last few years have, like bash, been limited only by available memory.

7

Chris -

With regard to arrays -

I disagree. Simply because you can NOT do something and have it work doesn't necessarily mean it is a great idea. There is a concept: self-documenting code.

Yes, syntactically, you are correct. In terms of good practice you are not. IMO.
You obviously do not buy this idea, so it's okay. Perderabo & I have gone around on this as well.

My point: In real world shops, especially now, people come & go & get outsourced.
Harder to read code is harder to maintain. Period. See 'Code Complete' by Steve McConnell 2nd Ed. Small changes to improve readability matter in the long run because 95% of the cost of software is in maintenance....

Unless this is a massive system operation running in an environment where you need to limit process resource usage as much as possible, code obfuscation in an attempt to gain performance is not de facto a good idea always. Not that this example makes much difference performance wise. Just coding for the 'next guy'.

8

So far there is not much happiness. This is the code:

#!/bin/sh

# read in text from file
lyrics=( $( <  _open.txt ) )

exit 0

and this is the output:

./clean.sh: 4: Syntax error: word unexpected (expecting ")")

So I am still eager to know what is causing this error.

9

You are executing the script with a shell that doesn't have arrays (or at least doesn't understand that syntax for populating them.

Change the shebang to a shell that supports it (e.g., #!/bin/bash).

10

In my books, "good practice" includes portability. If the portable code is not as clear, then a comment will make it so.