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| -rw-r--r-- | Doc/Zsh/redirect.yo | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Doc/Zsh/redirect.yo b/Doc/Zsh/redirect.yo index 35fa773fd..66160a61e 100644 --- a/Doc/Zsh/redirect.yo +++ b/Doc/Zsh/redirect.yo @@ -234,6 +234,25 @@ example(date >foo | cat) writes the date to the file `tt(foo)', and also pipes it to cat. +Note also that redirections are always expanded in order. This happens +regardless of the setting of the tt(MULTIOS) option, but with the option +in effect there are additional consequences. For example, +the meaning of the expression tt(>&1) will change after a previous +redirection: + +example(date >&1 >output) + +In the case above, the tt(>&1) refers to the standard output at the +start of the line; the result is similar to the tt(tee) command. +However, consider: + +exmaple(date >output >&1) + +As redirections are evaluated in order, when the tt(>&1) is encountered +the standard output is set to the file tt(output) and another copy of +the output is therefore sent to that file. This is unlikely to be what +is intended. + If the tt(MULTIOS) option is set, the word after a redirection operator is also subjected to filename generation (globbing). Thus |