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Can anyone explain difference between declare and typeset with real life examples .

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In bash, typeset and declare are exactly the same. The only difference is that typeset is considered obsolete.

typeset: typeset [-aAfFgilrtux] [-p] name[=value] ...
    Set variable values and attributes.

    Obsolete.  See `help declare'.

The man page even lists them in the same breath:

declare [-aAfFgilrtux] [-p] [name[=value] ...]
typeset [-aAfFgilrtux] [-p] [name[=value] ...]
    Declare variables and/or give them attributes.

typeset is portable to some other shells, for example, ksh93. If you are aiming for cross-shell portability, use typeset (and make sure that the way you are calling it is portable). If you don't care about such portability, use declare.

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  • can you please provide some example of where and why this use in bash script
    – Rahul Patil
    Feb 25, 2013 at 8:54
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    ...like I said, they are exactly the same. I don't understand how I can differentiate them if they are so.
    – Chris Down
    Feb 25, 2013 at 10:04
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    Good one. Note that "obsolete" just appears in help typeset, not in man typeset.
    – fedorqui
    Jul 22, 2014 at 8:05
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    @ChrisDown, you wouldn't happen to know why, exactly, typeset is considered obsolete?
    – Alexej Magura
    Oct 5, 2016 at 2:40
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    In bash 4.4 and later, it is changed to synonym instead of obsolete. help typeset => A synonym for `declare'. See `help declare'.
    – Koichi Nakashima
    Aug 20, 2021 at 11:14
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I know a case where declare is useful to avoid the evil eval : variable indirection :

$ var=foo
$ x=var
$ declare "$x=another_value"
$ echo $var
another_value
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  • This is a nice comment but how does that answer the question which is about typeset and declare?
    – jw013
    Feb 25, 2013 at 16:40
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    This is already well answered by Chris Down, my response is just a case where it's usefull
    – Gilles Quenot
    Feb 25, 2013 at 17:31
  • Perhaps I wasn't clear. Comments should be comments, and answers should be answers. This is a comment, not an answer.
    – jw013
    Feb 25, 2013 at 20:32
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    My snippet wouldn't clear in a comment
    – Gilles Quenot
    Feb 25, 2013 at 21:52
  • but you still can assign variables with typeset... just replace declare with typeset and you still get the same result.
    – pcarvalho
    Nov 28, 2017 at 15:14

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