I have a large file with many scattered file paths that look like
我有一个大文件，其中有许多分散的文件路径
lolsed_bulsh.png
I want to prepend these file names with an extended path like:
我想在这些文件名前面加上一个扩展路径，如:
/full/path/lolsed_bullsh.png
I'm having a hard time matching and capturing these. currently i'm trying variations of:
我很难匹配和捕捉这些。目前我正在尝试以下的变体:
cat myfile.txt| sed s/\(.+\)\.png/\/full\/path\/\1/g | ack /full/path
I think sed has some regex or capture group behavior I'm not understanding
我认为sed有一些regex或捕获组行为，我不理解
3 个解决方案
#1
5
sed uses POSIX BRE, and BRE doesn't support one or more quantifier +. The quantifier + is only supported in POSIX ERE. However, POSIX sed uses BRE and has no option to switch to ERE.
sed使用POSIX BRE，而BRE不支持一个或多个量词+。量词+仅在POSIX ERE中被支持。然而，POSIX sed使用BRE，无法切换到ERE。
Use ..* to simulate .+ if you want to maintain portability.
使用. .*模拟。+如果你想保持可移植性。
Or if you can assume that the code is always run on GNU sed, you can use GNU extension .\+. Alternatively, you can also use the GNU extension -r flag to switch to POSIX ERE. The -E flag in higuaro's answer is an undocumented flag for compatibility with BSD sed with the same effect.
或者，如果您可以假设代码总是在GNU sed上运行，那么您可以使用GNU扩展。\+。或者，也可以使用GNU扩展-r标志切换到POSIX ERE。在higuaro的答案中，-E标志是一个与BSD兼容的无文档标志，具有相同的效果。
#2
10
In your regex change + with *:
在您的regex更改+ with *中:
sed -E "s/(.*)\.png/\/full\/path\/\1/g" <<< "lolsed_bulsh.png"
It prints:
它打印:
/full/path/lolsed_bulsh
NOTE: The non standard -E option is to avoid escaping ( and )
注意:非标准的-E选项是避免转义(和)
#3
1
Save yourself some escaping by choosing a different separator (and -E option), for example:
通过选择不同的分隔符(和-E选项)为自己节省一些转义，例如:
cat myfile.txt | sed -E "s|(..*)\.png|/full/path/\1|g" | ack /full/path
#1
5
sed uses POSIX BRE, and BRE doesn't support one or more quantifier +. The quantifier + is only supported in POSIX ERE. However, POSIX sed uses BRE and has no option to switch to ERE.
sed使用POSIX BRE，而BRE不支持一个或多个量词+。量词+仅在POSIX ERE中被支持。然而，POSIX sed使用BRE，无法切换到ERE。
Use ..* to simulate .+ if you want to maintain portability.
使用. .*模拟。+如果你想保持可移植性。
Or if you can assume that the code is always run on GNU sed, you can use GNU extension .\+. Alternatively, you can also use the GNU extension -r flag to switch to POSIX ERE. The -E flag in higuaro's answer is an undocumented flag for compatibility with BSD sed with the same effect.
或者，如果您可以假设代码总是在GNU sed上运行，那么您可以使用GNU扩展。\+。或者，也可以使用GNU扩展-r标志切换到POSIX ERE。在higuaro的答案中，-E标志是一个与BSD兼容的无文档标志，具有相同的效果。
#2
10
In your regex change + with *:
在您的regex更改+ with *中:
sed -E "s/(.*)\.png/\/full\/path\/\1/g" <<< "lolsed_bulsh.png"
It prints:
它打印:
/full/path/lolsed_bulsh
NOTE: The non standard -E option is to avoid escaping ( and )
注意:非标准的-E选项是避免转义(和)
#3
1
Save yourself some escaping by choosing a different separator (and -E option), for example:
通过选择不同的分隔符(和-E选项)为自己节省一些转义，例如:
cat myfile.txt | sed -E "s|(..*)\.png|/full/path/\1|g" | ack /full/path