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after typing ;ls

I got this return - bash: syntax error near unexpected token `;'

how do I fix this?

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  • 4
    Why are you typing it? What are you going to achieve? – Arkadiusz Drabczyk Apr 6 at 12:35
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    Did you mean to type ;ls? If so, why? The easy answer is along the lines of "don't do that", but has deeper explanations, depending on your curiosity. – Jeff Schaller Apr 6 at 12:35
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    You could type :;ls instead... Or use Ksh or Zsh, which just ignore the empty command. It's somewhat interesting actually that it isn't allowed. – ilkkachu Apr 6 at 12:49
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    If you were to change that question from "How do I fix this?", which has the easy reply of "Don't do that", to "Why is this?" you'd have a really good question – roaima Apr 6 at 13:34
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The semicolon terminates a command. Usually you don't need it, since a newline will do. But you can use to put multiple commands on one line, e.g.

$ echo -n "hi "; echo there
hi there

or maybe more usefully:

if [ whatever ]; then

Putting a semicolon at the start of a line leaves an "empty" command before it, and apparently the shell syntax forbids it. Yash gives a useful error message:

$ yash -c '; echo hi'
yash -c:1: syntax error: a command is missing before ‘;’

And Ksh and Zsh seem to just ignore the issue:

$ zsh -c '; echo hi'
hi

(But you can't use echo foo;; in those either, since ;; is different from ;, like > is different from >>. ;; is used in case statements.)

The empty command doesn't do anything anyway, so you can just leave the leading semicolon out. Or switch to Zsh, I guess.

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  • Note that ksh93 -c 'echo test |; cat' complains but zsh doesn't. In any case, I wouldn't use it anyway as |; may become a new operator in future versions of either shell (like <>; and >; are already special operators in ksh93). – Stéphane Chazelas Apr 6 at 13:43
  • @StéphaneChazelas, or echo test | ; cat with the space. Or for x in 1 2 3 4; ; do; ; echo $x; done. In Zsh, I mean. I can see some sense in treating a semicolon a bit like a newline in that there can be many, but within a pipeline it seems a bit weird. At least it doesn't allow sprinkling & around in the same way... – ilkkachu Apr 6 at 14:41
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    See also array=( ; a ; ; ; b ). It seems ; is equivalent to newline in most places which is kind of consistent (though I agree a bit surprising) – Stéphane Chazelas Apr 6 at 14:44
  • The ; in echo one; echo two is a control character. The ; in if list; then ... is part of the if syntax. They are different, not equivalent. – Isaac Apr 8 at 5:40
  • @Isaac, not really, see also if cmd & then... (if cmd |& then in ksh). The point is that those ;, &, newline, |&... still delimit the commands there, and the then keyword, like most keywords is only recognised as such in command position (though that's not the whole story as if (true) then echo true; fi works in most shells (and YMMV for ((1)) or [[ x ]] in place of (true))) – Stéphane Chazelas Apr 8 at 7:17
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It is the same syntax error as:

$ ;
bash: syntax error near unexpected token `;'

Which simply means that there should be a cmd before the terminating ;:

$ ls ;

In such cases the ; is a metacharacter that is defined as:

metacharacter
A character that, when unquoted, separates words.

Not equivalent to the ; in the compound command:

if list; then list; else list; fi

As, in this case, it is part of the syntax of the command.

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