@@ -3,8 +3,8 @@ Bash POSIX Mode
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Starting Bash with the `--posix' command-line option or executing `set
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-o posix' while Bash is running will cause Bash to conform more closely
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- to the POSIX.2 standard by changing the behavior to match that
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- specified by POSIX.2 in areas where the Bash default differs.
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+ to the POSIX 1003 .2 standard by changing the behavior to match that
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+ specified by POSIX in areas where the Bash default differs.
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The following list is what's changed when `POSIX mode' is in effect:
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@@ -19,16 +19,16 @@ The following list is what's changed when `POSIX mode' is in effect:
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4. Reserved words may not be aliased.
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- 5. The POSIX.2 `PS1' and `PS2' expansions of `!' to the history
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+ 5. The POSIX 1003 .2 `PS1' and `PS2' expansions of `!' to the history
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number and `!!' to `!' are enabled, and parameter expansion is
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performed on the values of `PS1' and `PS2' regardless of the
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setting of the `promptvars' option.
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6. Interactive comments are enabled by default. (Bash has them on by
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default anyway.)
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- 7. The POSIX.2 startup files are executed (`$ENV') rather than the
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- normal Bash files.
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+ 7. The POSIX 1003 .2 startup files are executed (`$ENV') rather than
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+ the normal Bash files.
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8. Tilde expansion is only performed on assignments preceding a
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command name, rather than on all assignment statements on the line.
@@ -48,49 +48,52 @@ The following list is what's changed when `POSIX mode' is in effect:
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13. Redirection operators do not perform filename expansion on the word
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in the redirection unless the shell is interactive.
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- 14. Function names must be valid shell `name's. That is, they may not
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+ 14. Redirection operators do not perform word splitting on the word in
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+ the redirection.
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+
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+ 15. Function names must be valid shell `name's. That is, they may not
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contain characters other than letters, digits, and underscores, and
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may not start with a digit. Declaring a function with an invalid
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name causes a fatal syntax error in non-interactive shells.
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- 15 . POSIX.2 `special' builtins are found before shell functions during
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- command lookup.
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+ 16 . POSIX 1003 .2 `special' builtins are found before shell functions
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+ during command lookup.
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- 16 . If a POSIX.2 special builtin returns an error status, a
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+ 17 . If a POSIX 1003 .2 special builtin returns an error status, a
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non-interactive shell exits. The fatal errors are those listed in
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the POSIX.2 standard, and include things like passing incorrect
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options, redirection errors, variable assignment errors for
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assignments preceding the command name, and so on.
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- 17 . If the `cd' builtin finds a directory to change to using
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+ 18 . If the `cd' builtin finds a directory to change to using
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`$CDPATH', the value it assigns to the `PWD' variable does not
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contain any symbolic links, as if `cd -P' had been executed.
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- 18 . If `$CDPATH' is set, the `cd' builtin will not implicitly append
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+ 19 . If `$CDPATH' is set, the `cd' builtin will not implicitly append
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the current directory to it. This means that `cd' will fail if no
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valid directory name can be constructed from any of the entries in
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`$CDPATH', even if the a directory with the same name as the name
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given as an argument to `cd' exists in the current directory.
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- 19 . A non-interactive shell exits with an error status if a variable
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+ 20 . A non-interactive shell exits with an error status if a variable
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assignment error occurs when no command name follows the assignment
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statements. A variable assignment error occurs, for example, when
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trying to assign a value to a readonly variable.
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- 20 . A non-interactive shell exits with an error status if the iteration
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+ 21 . A non-interactive shell exits with an error status if the iteration
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variable in a `for' statement or the selection variable in a
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`select' statement is a readonly variable.
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- 21 . Process substitution is not available.
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+ 22 . Process substitution is not available.
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- 22 . Assignment statements preceding POSIX.2 special builtins persist
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- in the shell environment after the builtin completes.
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+ 23 . Assignment statements preceding POSIX 1003 .2 special builtins
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+ persist in the shell environment after the builtin completes.
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- 23 . The `export' and `readonly' builtin commands display their output
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- in the format required by POSIX.2.
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+ 24 . The `export' and `readonly' builtin commands display their output
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+ in the format required by POSIX 1003 .2.
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- There is other POSIX.2 behavior that Bash does not implement.
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+ There is other POSIX 1003 .2 behavior that Bash does not implement.
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Specifically:
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1. Assignment statements affect the execution environment of all
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