"syntax near unexpected token `{cd'" defining shell function

Question

Following advices I got from my previous post,I wrote a bash script

#!/bin/bash

mycd() 
{cd /home/milenko/data;}

mycd

./p2

p2 is executable

But

milenko@milenko-HP-Compaq-6830s:~$ bash a1.sh
a1.sh: line 4: syntax error near unexpected token `{cd'
a1.sh: line 4: `{cd /home/milenko/data;}'

Why?

Spaces are relevant, see the example in Charles' comment on your last question. — Benjamin W., Aug 08 '16 at 21:16
@BenjaminW. Ok,spaces are relevant but what empty space mean? — Richard Rublev, Aug 08 '16 at 21:18
An empty space separates two words. The first word in a command is syntax that determines what that command *is*. You can't run `{cd` and expect it to be identical to `cd` any more than you can run `acd` and expect it to do the same as `cd`. — Charles Duffy, Aug 08 '16 at 21:23
`{` has different meaning in `bash` depending on whether it has a space after it. — Barmar, Aug 08 '16 at 21:24
[shellcheck](http://www.shellcheck.net) automatically points out issues like this. — that other guy, Aug 08 '16 at 21:29
It would be perfectly legal (but a bad idea) to have a command named `{cd`. — Keith Thompson, Aug 08 '16 at 21:57
See [Simple logical operators in BASH](http://stackoverflow.com/questions/6270440/simple-logical-operators-in-bash/6270803#6270803) — Gilles 'SO- stop being evil', Aug 08 '16 at 22:30

Charles Duffy · Accepted Answer · 2016-08-08T21:45:37.800

Shell syntax (not just bash, but in POSIX sh) is built around units called "words". { only has its syntactic meaning when parsed as its own word -- meaning it needs to be surrounded by whitespace (a category which includes newlines).

The conventional way to write this would be:

mycd() {
  cd /home/milenko/data
}

...or, if you wanted to minimize newlines:

mycd() { cd /home/milenko/data; }

You could remove the space between the final ; and closing } (since ;, when found outside quotes and not escaped, ends any word which was preceding it), but this would be considered ugly:

mycd() { cd /home/milenko/data;} # leaving out the last space is legal, but please don't.

"syntax near unexpected token `{cd'" defining shell function

1 Answers1