Question

我第一次尝试使用sed进行多行替换。我发现了一些好的指针（general multiline help和multiline between two strings）。使用它作为启动器，我有以下命令：

sed '
/<dependency>/,/<\/dependency>/ { # Find a set of lines for a dependency
    s/\(<artifactId>\)m[^<]*\(<\/artifactId>\)/\1ARTIFACTID\2/ # Substitute if artifactId starts with 'm'
    t depend-update # If we substituted, go to depend-update.  Otherwise, continue
    :depend-unchanged
    s/\(<groupId>\)[^<]*\(<\/groupId>\)/\1CHANGE_A\2/ # Change groupId to have 'A'
    b # branch to end
:depend-update
    s/\(<groupId>\)[^<]*\(<\/groupId>\)/\1CHANGE_B\2/ # Change groupID to have 'B'
    b # branch to end
}
' \
inputfile.xml

我的输入文件包含以下内容：

<dependency>
    <groupId>foo</groupId>
    <artifactId>test.a</artifactId>
</dependency>
<dependency>
    <groupId>bar</groupId>
    <artifactId>mytest.a</artifactId>
</dependency>
<dependency>
    <groupId>baz</groupId>
    <artifactId>test.b</artifactId>
</dependency>

不幸的是，对于所有部分，我得到了＆＃34; CHANGE_A＆＃34;。据我了解，这意味着sed总是认为第一个替换什么也没做，即使它确实如此。结果是：

        <dependency>
            <groupId>CHANGE_A</groupId>
            <artifactId>test.a</artifactId>
        </dependency>
        <dependency>
            <groupId>CHANGE_A</groupId>
            <artifactId>ARTIFACTID</artifactId>
        </dependency>
        <dependency>
            <groupId>CHANGE_A</groupId>
            <artifactId>test.b</artifactId>
        </dependency>

我哪里出错了？

Answer 1

多行是由于“问题”导致在strem /文件输入上逐行工作而不是整体。在你的情况下，你处理一个行，但一次仍然是1行而不是块

/ startBlock /，/ EndBlock /表示只是，处理那些2个分隔符内的所有行，而不是将块分组在1个大块中

以下是提议的改编

sed '
/<dependency>/,\#</dependency># {
# load into the buffer
    /<dependency>/ h;/<dependency>/ !H
    \#</dependency># {
# At end of block, load the buffer and work on it
    g

# Find a set of lines for a dependency
        s/\(<artifactId>\)m[^<]*\(<\/artifactId>\)/\1ARTIFACTID\2/ # Substitute if artifactId starts with 'm'
        t depend-update # If we substituted, go to depend-update.  Otherwise, continue
:depend-unchanged
        s/\(<groupId>\)[^<]*\(<\/groupId>\)/\1CHANGE_A\2/ # Change groupId to have 'A'
# branch to end
        b # branch to end
:depend-update
        s/\(<groupId>\)[^<]*\(<\/groupId>\)/\1CHANGE_B\2/ # Change groupID to have 'B'
# branch to end
        b
        }
    }
' \
inputfile.xml

具有多线段的sed条件分支

1 个答案: