Question

我是iOS开发人员，不熟悉Linux，我搜索了很长时间但仍然无法解决我的问题。我希望有人可以帮助我，谢谢！

删除前：

Other contents......

#
# Proxy server for iTerm & Terminal Setup Script
# version 0.1
# VincentSit
# Nov 26, 2014
#
function start_proxy {
 export http_proxy='abc.efgh.com:1234'
 export HTTPS_PROXY='abc.efgh.com:1234'
 }

function stop_proxy {
 export http_proxy=''
 export HTTPS_PROXY=''
 }

Other contents......

删除后：

Other contents......
Other contents......

更新

我正在编写 shell 脚本（不能使用其他语言）。在用户系统上有一个名为abc的文本文件，内容可能是这样的：

# Other comments......
# Other comments......
# Other comments......
Other contents......
# Other comments......

#
# Proxy server for iTerm & Terminal Setup Script
# version 0.1
# VincentSit
# Nov 26, 2014
#
function start_proxy {
 export http_proxy='abc.efgh.com:1234'
 export HTTPS_PROXY='abc.efgh.com:1234'
 }

function stop_proxy {
 export http_proxy=''
 export HTTPS_PROXY=''
 }

# Other comments......
Other contents......
# Other comments......
# Other comments......

哪个Other contents ......是虚构的，不能将其用作已删除的条件。

我只需要删除以下部分：

#
# Proxy server for iTerm & Terminal Setup Script
# version 0.1
# VincentSit
# Nov 26, 2014
#
function start_proxy {
 export http_proxy='abc.efgh.com:1234'
 export HTTPS_PROXY='abc.efgh.com:1234'
 }

function stop_proxy {
 export http_proxy=''
 export HTTPS_PROXY=''
 }

不需要删除此文件中的其他内容。

因为它在用户的系统上运行，所以我不知道要删除的内容的行号。

最后看起来像这样：

# Other comments......
# Other comments......
# Other comments......
Other contents......
# Other comments......

# Other comments......
Other contents......
# Other comments......
# Other comments......

我认为答案可能如下：

sed xxxxxx abc.txt

awk xxxxxx abc.txt

Answer 1

这是一个Perl解决方案。

perl -0777 -pe 's/\n+(#.*\n)*\n*function\s+start_proxy\s*\{(.*\n)+?function\s+stop_proxy\s*\{(.*\n)+?\s*\}//'

与之前发布的sed解决方案相比，它更精确，也更省内存，因为它在处理之前将整个文件读入内存。

正则表达式试图寻找

\n+之前的所有空行...
(#.*\n)* ...任意数量的评论行，以#开头，后跟......
\n* ...之前可选的空行...
function\s+start_proxy\s*\{
(.*\n)+? ...尽可能少的行到......
function\s+stop_proxy\s\{
(.*\n)+? ...并且尽可能少的行直到......
\s*\} ...以下结束括号。

量词+?寻找最短的匹配，而不仅仅是+，它总是抓住最长的匹配（贪婪的匹配）。

Answer 2

您可以使用行号范围删除不必要的行。

示例：

sdlcb@Goofy-Gen:~/AMD/SO$ cat File This is Line 1 This is Line 2 This is Line 3 This is Line 4 This is Line 5 This is Line 6 This is Line 7 sdlcb@Goofy-Gen:~/AMD/SO$ sed -i.bak '3,6d' File sdlcb@Goofy-Gen:~/AMD/SO$ cat File This is Line 1 This is Line 2 This is Line 7

删除第3到第6行。

否则：

sed -n '/^Other contents/,/^Other contents/{ /^Other contents/!d; /^Other contents/!d; p; }' File

<强>详细信息：

-n option => do not print /a/,/b/ => select lines between the lines matching /a/ and /b/ (inclusive) /a/!d => delete lines not matching /a/ /b/!d => delete lines not matching /b/ in our case a and b = '^Other contents' which means beginning with 'Other contents' p => print

示例：

sdlcb@Goofy-Gen:~/AMD/SO$ cat File Other contents...... # # Proxy server for iTerm & Terminal Setup Script # version 0.1 # VincentSit # Nov 26, 2014 # function start_proxy { export http_proxy='abc.efgh.com:1234' export HTTPS_PROXY='abc.efgh.com:1234' } function stop_proxy { export http_proxy='' export HTTPS_PROXY='' } Other contents...... sdlcb@Goofy-Gen:~/AMD/SO$ sed -n '/^Other contents/,/^Other contents/{ /^Other contents/!d; /^Other contents/!d; p; }' File Other contents...... Other contents......

Answer 3

我会做像

这样的事情

$ sed '/^#/d; /^function/, /}/ d; /^$/d ' input
Other contents......
Other contents......

它的作用是什么？

d删除模式空间。
^#匹配以#
/^function/, /}/指定范围
^$匹配空行

修改

$ sed ' /^#$/d; /^# Proxy/, /}/d; /function stop_proxy/, /}/ d ' input # Other comments...... # Other comments...... # Other comments...... Other contents...... # Other comments...... # Other comments...... Other contents...... # Other comments...... # Other comments......

注意上述解决方案有一个限制，即删除没有内容的空注释

#

Answer 4

这将严格删除您要求的内容：

$ cat bad
#
# Proxy server for iTerm & Terminal Setup Script
# version 0.1
# VincentSit
# Nov 26, 2014
#
function start_proxy {
 export http_proxy='abc.efgh.com:1234'
 export HTTPS_PROXY='abc.efgh.com:1234'
 }

function stop_proxy {
 export http_proxy=''
 export HTTPS_PROXY=''
 }

$ cat file
# Other comments......
# Other comments......
# Other comments......
Other contents......
# Other comments......

#
# Proxy server for iTerm & Terminal Setup Script
# version 0.1
# VincentSit
# Nov 26, 2014
#
function start_proxy {
 export http_proxy='abc.efgh.com:1234'
 export HTTPS_PROXY='abc.efgh.com:1234'
 }

function stop_proxy {
 export http_proxy=''
 export HTTPS_PROXY=''
 }

# Other comments......
Other contents......
# Other comments......
# Other comments......

$ awk -v RS='^$' -v ORS= 'NR==FNR{bad=$0;next} s=index($0,bad){$0=substr($0,1,s-1) substr($0,s+length(bad))} 1' bad file
# Other comments......
# Other comments......
# Other comments......
Other contents......
# Other comments......

# Other comments......
Other contents......
# Other comments......
# Other comments......
$

它使用GNU awk进行多字符RS。如果需要的话，它也很容易在其他方面做到，但在我们发现这是否是您正在寻找的解决方案之前不会付出努力。

字符串中的错误：

$ awk -v RS='^$' -v ORS= -v bad="#
# Proxy server for iTerm & Terminal Setup Script
# version 0.1
# VincentSit
# Nov 26, 2014
#
function start_proxy {
 export http_proxy='abc.efgh.com:1234'
 export HTTPS_PROXY='abc.efgh.com:1234'
 }

function stop_proxy {
 export http_proxy=''
 export HTTPS_PROXY=''
 }

" 's=index($0,bad){$0=substr($0,1,s-1) substr($0,s+length(bad))} 1' file
# Other comments......
# Other comments......
# Other comments......
Other contents......
# Other comments......

# Other comments......
Other contents......
# Other comments......
# Other comments......

linux删除文件中的多行

4 个答案: