問題請教

Brevity

在看《linux shell腳本攻略》，書上說 cmd 2>&1 output.txt和cmd &> output.txt功能一樣，但是在ubuntu環(huán)境下，前面一個語句不能執(zhí)行完成，后面一個能夠執(zhí)行完成。

這時咋回事？？兩個語句的功能到底一樣不？

Brevity

2樓的，我的前面一個語句有錯誤？

hbmhalley

Redirecting Standard Output and Standard Error

This construct allows both the standard output (file descriptor 1) and the standard error output (file descriptor 2) to be redirected to the file whose name is the expansion of word.
There are two formats for redirecting standard output and standard error:

&>word
and
>&word
Of the two forms, the first is preferred. This is semantically equivalent to
>word 2>&1

man bash(1)

shell_heaven

a:  
    command &>$filename

b:
    command >$filename  2>&1

c:
    command 2>$filename  >&2