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author | Chet Ramey <chet.ramey@case.edu> | 2011-12-03 13:39:30 -0500 |
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committer | Chet Ramey <chet.ramey@case.edu> | 2011-12-03 13:39:30 -0500 |
commit | ec2199bd304f0d91c17efe2aac899781a4b603f3 (patch) | |
tree | 9eb9bf3e5c6407511343a13d5c254025c2b02d78 /doc/bashref.texi~ | |
parent | d11b8b46f070695ffdc25a9a49f0b2dacd948273 (diff) | |
download | bash-ec2199bd304f0d91c17efe2aac899781a4b603f3.tar.gz |
commit bash-20041111 snapshot
Diffstat (limited to 'doc/bashref.texi~')
-rw-r--r-- | doc/bashref.texi~ | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/doc/bashref.texi~ b/doc/bashref.texi~ index b581aaab..fe170764 100644 --- a/doc/bashref.texi~ +++ b/doc/bashref.texi~ @@ -1208,6 +1208,21 @@ Assignment statements may also appear as arguments to the @code{declare}, @code{typeset}, @code{export}, @code{readonly}, and @code{local} builtin commands. +In the context where an assignment statement is assigning a value +to a shell variable or array index (@pxref{Arrays}), the @samp{+=} +operator can be used to +append to or add to the variable's previous value. +When @samp{+=} is applied to a variable for which the integer attribute +has been set, @var{value} is evaluated as an arithmetic expression and +added to the variable's current value, which is also evaluated. +When @samp{+=} is applied to an array variable using compound assignment +(@pxref{Arrays}), the +variable's value is not unset (as it is when using @samp{=}), and new +values are appended to the array beginning at one greater than the array's +maximum index. +When applied to a string-valued variable, @var{value} is expanded and +appended to the variable's value. + @node Positional Parameters @subsection Positional Parameters @cindex parameters, positional @@ -1584,6 +1599,8 @@ parameters beginning at @var{offset}. If @var{parameter} is an array name indexed by @samp{@@} or @samp{*}, the result is the @var{length} members of the array beginning with @code{$@{@var{parameter}[@var{offset}]@}}. +A negative @var{offset} is taken relative to one greater than the maximum +index of the specified array. Substring indexing is zero-based unless the positional parameters are used, in which case the indexing starts at 1. |