[英]Escaping question mark character in sed bash script variable
I have a set of saved html files with links in them of the form http://mywebsite.com/showfile.cgi?key=somenumber but I want to kill the question mark (side-story is that firefox hates ? and randomly converts it to %3F I'm sure there's some magic fix but that's for another question...) 我有一组保存的html文件,它们中的链接的格式为http://mywebsite.com/showfile.cgi?key=somenumber,但我想取消问号(故事是Firefox讨厌?并随机转换它到%3F,我确定有一些魔术修复方法,但这是另一个问题……)
However, I think my code is causing the question-mark character to not be read/saved/handled properly when storing the options as a variable by bash 但是,我认为当bash将选项存储为变量时,我的代码导致问号字符无法正确读取/保存/处理
# Doesn't work (no pattern matched)
SED_OPTIONS='-i s/\.cgi\?key/\.cgikey/g'
# Works e.g. http://mywebsite.com/showfileblah?key=somenumber
SED_OPTIONS='-i s/\.cgi/blah/g'
# Leaves question mark in e.g. http://mywebsite.com/showfile.blah?key=somenumber
SED_OPTIONS='-i s/cgi\?/blah/g'
# Actual sed command run when using SED_OPTIONS (I define FILES earlier in
# the code)
sed $SED_OPTIONS $FILES
# Not using the SED_OPTIONS variable works
# e.g. http://mywebsite.com/showfile.cgikey=somenumber
sed -i s/\.cgi\?key/\.cgikey/g $FILES
How can I get the full command to work using the SED_OPTIONS variable? 如何使用SED_OPTIONS变量使完整命令起作用?
The safest way to store a list of options and arguments in variables is to use an array : 在变量中存储选项和参数列表的最安全方法是使用数组 :
Also: 也:
-r
or -E
option), so ?
-r
或-E
选项),所以?
is not a special char. .
.
. g
, since you're only replacing 1 occurrence per line. g
,因为您只需要替换每行1次即可。 # Create array with individual options/arguments.
SED_ARGS=( '-i' 's/\.cgi?key/.cgikey/' )
# Invoke `sed` with array - note the double-quoting.
sed "${SED_ARGS[@]}" $FILES
Similarly, it would be safer to use an array for the list of input files. 同样,将数组用于输入文件列表会更安全。
$FILES
will only work if the individual filenames contain no embedded whitespace or other elements subject to shell expansions. 仅当单个文件名不包含嵌入式空格或其他受Shell扩展限制的元素时,
$FILES
才起作用。
Generally: 通常:
sed
script here - to prevent the shell from interpreting them. sed
脚本-防止shell解释它们。 I suggest storing the arguments for sed
in an array: 我建议将
sed
的参数存储在数组中:
SED_OPTIONS=( '-i' '-e' 's/\.cgi?key/\.cgikey/g' )
sed "${SED_OPTIONS[@]}" $FILES
However, that's only a part of the trouble. 但是,那只是麻烦的一部分。
First, note that when you type: 首先,请注意当您键入:
sed -i s/\.cgi\?key/\.cgikey/g $FILES
what sed
sees as the script argument is actually: sed
看到的script参数实际上是:
s/.cgi?key/.cgikey/g
because you didn't use any quotes to preserve the backslashes. 因为您没有使用任何引号来保留反斜杠。 (To demonstrate, use
printf "%s\\n" s/\\.cgi\\?key/\\.cgikey/g
, thus avoiding any questions of whether echo
is interpreting the backslashes.) One side effect of this is that a URL such as: (为演示
printf "%s\\n" s/\\.cgi\\?key/\\.cgikey/g
,请使用printf "%s\\n" s/\\.cgi\\?key/\\.cgikey/g
,从而避免出现任何有关echo
是否正在解释反斜杠的问题。)这样做的副作用是URL这样如:
http://example.com/nodotcgi?key=value
will be mapped to: 将映射到:
http://example.com/nodo.cgikey=value
Using the single quotes when setting SED_OPTIONS ensures that the backslashes are preserved where required, and not putting a backslash before the ?
设置SED_OPTIONS时使用单引号可确保在需要的地方保留反斜杠,并且不要在
?
之前放置反斜杠?
works. 作品。 I have both GNU
sed
and BSD sed
on my Mac; 我的Mac上同时有GNU
sed
和BSD sed
。 I've aliased them as gnu-sed
and bsd-sed
for clarity. 为了清楚起见,我将它们别名为
gnu-sed
和bsd-sed
。 Note that BSD sed
requires a suffix for -i
and won't accept standard input with -i
. 请注意,BSD
sed
需要-i
的后缀,并且不接受-i
标准输入。 So, I've dropped the -i
from the commands. 因此,我从命令中删除了
-i
。
$ URLS=(http://example.com/script.cgi?key=value http://example.com/nodotcgi?key=value)
$ SED_OPTIONS=( '-e' 's/\.cgi?key/\.cgikey/g' )
$ printf "%s\n" "${URLS[@]}" | bsd-sed "${SED_OPTIONS[@]}"
http://example.com/script.cgikey=value
http://example.com/nodotcgi?key=value
$ printf "%s\n" "${URLS[@]}" | gnu-sed "${SED_OPTIONS[@]}"
http://example.com/script.cgikey=value
http://example.com/nodotcgi?key=value
$ SED_OPTIONS=( '-e' 's/\.cgi\?key/\.cgikey/g' )
$ printf "%s\n" "${URLS[@]}" | bsd-sed "${SED_OPTIONS[@]}"
http://example.com/script.cgikey=value
http://example.com/nodotcgi?key=value
$ printf "%s\n" "${URLS[@]}" | gnu-sed "${SED_OPTIONS[@]}"
http://example.com/script.cgi?key=value
http://example.com/nodotcgi?key=value
$
Note the difference in behaviour between the two versions of sed
when there's a backslash before the question mark (second part of the example). 请注意,当问号前有反斜杠时,两个版本的
sed
行为有所不同(示例的第二部分)。
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