bash sed - 删除破折号前的所有字符
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sed - delete all characters before dash
提问by scripting_newbie
I have list of filenames for which I want to remove all character before the first instance of -. So the names below in the Before: list appears as those in the After: list.
我有一个文件名列表，我想在第一个实例之前删除所有字符-。因此，Before: 列表中的以下名称显示为 After: 列表中的名称。
Before:
Adam James - Welcome Home.txt
Mike & Harry - One Upon - A Time.txt
William-Kent - Prince & The Frog.txt
After:
Welcome Home.txt
One Upon - A Time.txt
Prince & The Frog.txt
I've been playing around with sed for hours with no avail.
我一直在玩 sed 几个小时但无济于事。
I found that sed 's/ - .*//'removes all characters after the first instance of -but I cannot find the same for before.
我发现sed 's/ - .*//'在第一个实例之后删除了所有字符，-但我之前找不到相同的字符。
采纳答案by anubhava
Using awk you can do:
使用 awk，您可以执行以下操作：
awk 'BEGIN{FS=OFS="- "} NF>1{="";sub(/^- */, "")}'1 inFIle
Live Demo: http://ideone.com/2tBU4v
现场演示：http: //ideone.com/2tBU4v
回答by pdw
Like this.
像这样。
sed 's/^[^-]* - //'
Many regular expression engines allow *?for a non-greedy search, but sed doesn't.
许多正则表达式引擎允许*?非贪婪搜索，但 sed 不允许。
EDIT: This won't change the William-Kent example, the embedded hyphen prevents a match.
编辑：这不会改变 William-Kent 示例，嵌入的连字符会阻止匹配。
(Also, Perl ships a very handy renamescript to batch-rename files using regular expressions, but not every distribution installs it.)
（此外，Perl 提供了一个非常方便的rename脚本来使用正则表达式批量重命名文件，但并非每个发行版都安装了它。）
回答by Ed Morton
$ awk '{print substr($ grep -Po ' - \K.*' file
Welcome Home.txt
One Upon - A Time.txt
Prince & The Frog.txt
,index(awk -v FPAT="- .*$" 'sub(/^- /,"",)' file
," - ")+3)}' file
Welcome Home.txt
One Upon - A Time.txt
Prince & The Frog.txt
i.e. just print from the end of the first occurrence of " - " to the end of the line.
即只是从第一次出现的“-”的末尾打印到行的末尾。
回答by Chris Seymour
Simplest approach is too use grep:
最简单的方法太用了grep：
kent$ echo "Adam James - Welcome Home.txt
Mike & Harry - One Upon - A Time.txt
William-Kent - Prince & The Frog.txt"|awk -v FPAT="- .*$" 'sub(/^- /,"",)'
Welcome Home.txt
One Upon - A Time.txt
Prince & The Frog.txt
回答by Kent
I think gawkmay be easier for this job.
我认为gawk这份工作可能会更容易一些。
the usage of FPATcould simplify the problem:
的使用FPAT可以简化问题：
list=('Adam James - Welcome Home.txt' 'Mike & Harry - One Upon - A Time.txt')
for str in "${list[@]}"; do echo ${str#*-}; done
with your data:
使用您的数据：
Welcome Home.txt
One Upon - A Time.txt
回答by bobah
In pure Bash (no extra child processes spawned):
在纯 Bash 中（没有产生额外的子进程）：
$ cat the_file_names
Adam James - Welcome Home.txt
Mike & Harry - One Upon - A Time.txt
William-Kent - Prince & The Frog.txt
$ { while read FN; do echo ${FN#* - }; done; } < /tmp/the_file_names
Welcome Home.txt
One Upon - A Time.txt
Prince & The Frog.txt
$
Prints:
印刷：
sed 's/ - /\n/;s/.*\n//' file
回答by pilcrow
This can be done in plain POSIX sh, without bash features:
这可以在没有 bash 功能的普通 POSIX sh 中完成：
##代码##回答by potong
This might work for you (GNU sed):
这可能对你有用（GNU sed）：
##代码##