Bash - error message 'Syntax error: "(" unexpected'

Question

For some reason, this function is working properly. The terminal is outputting

newbootstrap.sh: 2: Syntax error: "(" unexpected

Here is my code (line 2 is function MoveToTarget() {)

#!/bin/bash
function MoveToTarget() {
    # This takes two arguments: source and target
    cp -r -f "$1" "$2"
    rm -r -f "$1"
}

function WaitForProcessToEnd() {
    # This takes one argument. The PID to wait for
    # Unlike the AutoIt version, this sleeps for one second
    while [ $(kill -0 "$1") ]; do
        sleep 1
    done
}

function RunApplication() {
    # This takes one application, the path to the thing to execute
    exec "$1"
}

# Our main code block
pid="$1"
SourcePath="$2"
DestPath="$3"
ToExecute="$4"
WaitForProcessToEnd $pid
MoveToTarget $SourcePath, $DestPath
RunApplication $ToExecute
exit

Re "this function is working properly": Don't you mean "this function is not working properly" (my emphasis)? — Peter Mortensen
– Peter Mortensen, Commented Nov 27, 2021 at 23:25

Peter Mortensen · Accepted Answer · 2021-11-27 23:27:47Z

36

You're using the wrong syntax to declare functions. Use this instead:

MoveToTarget() {
    # Function
}

Or this:

function MoveToTarget {
    # function
}

But not both.

Also, I see that later on you use commas to separate arguments (MoveToTarget $SourcePath, $DestPath). That is also a problem. Bash uses spaces to separate arguments, not commas. Remove the comma and you should be golden.

edited Nov 27, 2021 at 23:27

Peter Mortensen

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answered Jun 14, 2011 at 16:52

Rafe Kettler

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6 Comments

rsmith Over a year ago

Thanks! It makes sense now. I saw some websites that did that.

Jens Over a year ago

@rsmith Name the site or it was a dream :-)

qneill Over a year ago

See comments in stackoverflow.com/questions/7917018/… The "function" keyword is non-POSIX compliant, see "Shell Function Definitions" in the bash man page

林果皞 Over a year ago

Note also empty function body is not allow which is the most confusing part (since someone may narrow down to test empty body but still not working), see stackoverflow.com/questions/39307615/…

ruakh Over a year ago

Does this depend on the version of Bash? Bash 4.1.2 on my system is perfectly fine with function MoveToTarget() { ....

|

Peter Mortensen · Accepted Answer · 2021-11-27 23:30:06Z

5

I'm also new to defining functions in Bash scripts. I'm using a Bash of version 4.3.11(1):-release (x86_64-pc-linux-gnu) on Ubuntu 14.04 (Trusty Tahr).

I don't know why, but the definition that starts with the keyword function never works for me.

A definition like the following

function check_and_start {
  echo Hello
}

produces the error message:

Syntax error: "}" unexpected

If I put the { on a new line like:

function my_function
{
    echo Hello.
}

It prints a Hello. when I run the script, even if I don't call this function at all, which is also what we want.

I don't know why this wouldn't work, because I also looked at many tutorials and they all put the open curly brace at the end of the first line. Maybe it's the version of Bash that we use?? Anyway, just put it here for your information.

I have to use the C-style function definition:

check_and_start() {
  echo $1
}

check_and_start World!
check_and_start Hello,\ World!

and it works as expected.

edited Nov 27, 2021 at 23:30

Peter Mortensen

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answered Mar 2, 2016 at 20:31

yaobin

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1 Comment

Ifrit Over a year ago

I'm having the same exact issue. Dropping the word function and adding paran worked for me too. I noticed either function style will work fine on OS X. Though my OS X is running a much older version of bash.

Peter Mortensen · Accepted Answer · 2021-11-27 23:33:48Z

5

If you encounter "Syntax error: "(" unexpected", then use "bash" instead of using "sh".

For example:

bash install.sh

edited Nov 27, 2021 at 23:33

Peter Mortensen

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answered Jul 16, 2020 at 6:54

Mr Mayur

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4 Comments

Peter Mortensen Over a year ago

That will not help if your script is called by something else, e.g. a Git hooks pre-commit script.

Peter Mortensen Over a year ago

Alternative: Get the information from which bash and use, e.g., #!/usr/bin/bash instead of #!/bin/sh.

Peter Mortensen Over a year ago

#!/bin/bash may also work (as /bin may just point to /bin/usr).

Peter Mortensen Over a year ago

/bin/sh may point to Dash (dash) - observed on Ubuntu MATE 20.04 (Focal Fossa).

Peter Mortensen · Accepted Answer · 2021-11-27 23:32:16Z

0

I had the same issue. I was running scripts on Ubuntu sometimes using sh vs. Dash. It seems running scripts with sh causes the issue, but running scripts with Dash works fine.

edited Nov 27, 2021 at 23:32

Peter Mortensen

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answered May 6, 2019 at 23:13

user11461797

1

1 Comment

Peter Mortensen Over a year ago

Why is it different? Doesn't /bin/sh point to dash (symbolic link)?

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