sed 无法处理 ~user/.bash_profile答案

【问题标题】：sed not able to process ~user/.bash_profilesed 无法处理 ~user/.bash_profile
【发布时间】：2012-09-10 07:55:18
【问题描述】：

sed 有一个非常奇怪的问题，如果我这样做的话：

[root@Camel ~]-> sed -i 's/TLRAGENT_IP=.*/TLRAGENT_IP='"${HOST_IP}"'/' ~user/.bash_profile

没关系。但如果我尝试以下操作：

[root@Camel ~]-> CONF_FILE="~user/.bash_profile"
[root@Camel ~]-> sed -i 's/TLRAGENT_IP=.*/TLRAGENT_IP='"${HOST_IP}"'/' ${CONF_FILE}
sed: can't read ~user/.bash_profile: No such file or directory

还尝试引用变量：

[root@Camel ~]-> sed -i 's/TLRAGENT_IP=.*/TLRAGENT_IP='"${HOST_IP}"'/' "${CONF_FILE}"
sed: can't read ~user/.bash_profile: No such file or directory

不知道哪里出了问题，请指教。

Shell 的版本是3.2.25(1)-release。

【问题讨论】：

标签： bash sed home-directory

【解决方案1】：

来自man bash/EXPANSION

EXPANSION
 Expansion is performed on the command line after it has been
 split  into  words.  There are seven kinds of expansion per-
 formed:  brace expansion,  tilde  expansion,  parameter  and
 variable  expansion, command substitution, arithmetic expan-
 sion, word splitting, and pathname expansion.

 The order of expansions is: brace  expansion,  tilde  expan-
 sion,  parameter, variable and arithmetic expansion and com-
 mand substitution (done in a  left-to-right  fashion),  word
 splitting, and pathname expansion.

参数和变量扩展在波浪号扩展之后

要进行波浪号扩展，这可以在变量定义中完成

CONF_FILE=~user/.bash_profile

而不是

CONF_FILE="~user/.bash_profile"

【讨论】：