将 xml 转换为键值对表示法

Question

我使用xmlstarlet el -v 来显示一个xml 文件的结构，包括所有的属性和值。我想将其输出转换为某种键值对，即每个属性的值在单独的行上（包括 XPath）；每行必须是唯一的。

当前结果：

topRoot/topSystem/commSvcEp/commSyslog[@descr='Syslog Service' and @name='syslog' and @policyOwner='local' and @severity='critical']
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[@adminState='disabled' and @forwardingFacility='local7' and @hostname='none' and @name='secondary' and @severity='critical']
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[@adminState='disabled' and @forwardingFacility='local7' and @hostname='none' and @name='tertiary' and @severity='critical']
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[@adminState='disabled' and @forwardingFacility='local7' and @hostname='none' and @name='primary' and @severity='critical']

期望的结果（可以是任何类似的东西；索引只是一个想法）：

topRoot/topSystem/commSvcEp/commSyslog@descr='Syslog Service'
topRoot/topSystem/commSvcEp/commSyslog@name='syslog'
topRoot/topSystem/commSvcEp/commSyslog@policyOwner='local'
topRoot/topSystem/commSvcEp/commSyslog@severity='critical'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@adminState='disabled'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@forwardingFacility='local7'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@hostname='none'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@name='secondary'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@severity='critical'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@adminState='disabled'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@forwardingFacility='local7'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@hostname='none'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@name='tertiary'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@severity='critical'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@adminState='disabled'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@forwardingFacility='local7'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@hostname='none'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@name='primary'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@severity='critical'

我想要完成的是能够在两个这样的文件上运行 diff 或使用 grep 过滤匹配模式。我确信有一种方法可以创建这样的输出，而不使用 sed、awk 或除 xmlstarlet 本身之外的任何其他东西。

关于 xmlstarlet 和整个 xml 世界，我几乎是一个新手（不仅因为我不喜欢 xml，因为它的复杂性和解析开销等），所以我非常感谢你的帮助。谢谢！

Answer 1

由于您已经在使用xmlstarlet，您也可以使用 XSLT。

XSLT 1.0（可以通过使用tr 命令与xmlstarlet 一起运行）

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="text"/>
    <xsl:strip-space elements="*"/>

    <xsl:param name="sep" select="'.'"/>

    <xsl:template match="text()"/>

    <xsl:template match="*">
        <xsl:variable name="path">
            <xsl:for-each select="ancestor-or-self::*">
                <xsl:variable name="predicate">
                    <xsl:call-template name="genPredicate"/>
                </xsl:variable>
                <xsl:if test="ancestor::*">
                    <xsl:value-of select="$sep"/>
                </xsl:if>
                <xsl:value-of select="concat(local-name(),$predicate)"/>
            </xsl:for-each>
        </xsl:variable>
        <xsl:for-each select="@*">
            <xsl:value-of select="concat($path,$sep,name(),'=',.)"/>
            <xsl:text>&#xA;</xsl:text>
        </xsl:for-each>
        <xsl:if test="not(@*)">
            <xsl:text>&#xA;</xsl:text>          
        </xsl:if>
        <xsl:apply-templates select="node()"/>
    </xsl:template>

    <xsl:template name="genPredicate">
        <xsl:if test="preceding-sibling::*[local-name()=local-name(current())] or following-sibling::*[local-name()=local-name(current())]">
            <xsl:value-of select="concat('[',count(preceding-sibling::*[local-name()=local-name(current())])+1,']')"/>          
        </xsl:if>
    </xsl:template>

</xsl:stylesheet>

注意：有一个名为sep 的参数，因此您可以从命令行更改分隔符（使用-p sep="/" 或您想要的任何分隔符）。它目前设置为您首选的“.”。

输出

commSyslog.descr=Syslog Service
commSyslog.name=syslog
commSyslog.policyOwner=local
commSyslog.severity=critical
commSyslog.commSyslogClient[1].adminState=disabled
commSyslog.commSyslogClient[1].forwardingFacility=local7
commSyslog.commSyslogClient[1].hostname=none
commSyslog.commSyslogClient[1].name=secondary
commSyslog.commSyslogClient[1].severity=critical
commSyslog.commSyslogClient[2].adminState=disabled
commSyslog.commSyslogClient[2].forwardingFacility=local7
commSyslog.commSyslogClient[2].hostname=none
commSyslog.commSyslogClient[2].name=tertiary
commSyslog.commSyslogClient[2].severity=critical
commSyslog.commSyslogClient[3].adminState=disabled
commSyslog.commSyslogClient[3].forwardingFacility=local7
commSyslog.commSyslogClient[3].hostname=none
commSyslog.commSyslogClient[3].name=primary
commSyslog.commSyslogClient[3].severity=critical
commSyslog.commSyslogMonitor.adminState=disabled
commSyslog.commSyslogMonitor.descr=
commSyslog.commSyslogMonitor.name=
commSyslog.commSyslogMonitor.severity=critical
commSyslog.commSyslogConsole.adminState=disabled
commSyslog.commSyslogConsole.descr=
commSyslog.commSyslogConsole.name=
commSyslog.commSyslogConsole.severity=critical
commSyslog.commSyslogSource.audits=disabled
commSyslog.commSyslogSource.descr=
commSyslog.commSyslogSource.events=disabled
commSyslog.commSyslogSource.faults=enabled
commSyslog.commSyslogSource.name=
commSyslog.commSyslogFile.adminState=enabled
commSyslog.commSyslogFile.descr=
commSyslog.commSyslogFile.name=messages
commSyslog.commSyslogFile.severity=critical
commSyslog.commSyslogFile.size=4194304

Answer 2

我决定使用 libxml2 编写一个小程序，它解析 XML 并以所需的格式递归输出。

代码可以用下面的命令编译，或者类似的东西（我决定叫它xmlkv，kv代表key-value）：

cc -o xmlkv xmlkv.c -s -Os -Wall -Wextra `xml2-config --cflags --libs`

代码：

#include <stdlib.h>
#include <stdio.h>
#include <libxml/parser.h>
#include <libxml/tree.h>

static void print_elements(xmlNode *);

static void
print_elements(xmlNode *node)
{
    xmlNode *n;
    xmlAttrPtr a;
    xmlChar *v, *p, *q;

    for (n = node; n; n = n->next) {
        if (n->type == XML_ELEMENT_NODE) {
            if ((p = xmlGetNodePath(n)) == NULL)
                return;

            for (q = p; *q; q++)
                if (*q == '/')
                    *q = '.';

            for (a = n->properties; a; a = a->next) {
                if ((v = xmlGetProp(n, a->name)) == NULL)
                    return;

                printf("%s.%s=%s\n", p + 1, a->name, v);
                xmlFree(v);
            }

            xmlFree(p);
        }

        print_elements(n->children);
    }
}

int
main(int argc, char **argv)
{
    xmlDoc *doc = NULL;
    xmlNode *root = NULL;

    LIBXML_TEST_VERSION

    if (argc != 2) {
        fprintf(stderr, "usage: %s <file>\n", *argv);
        return EXIT_FAILURE;
    }

    if ((doc = xmlReadFile(argv[1], NULL, 0)) == NULL)
        return EXIT_FAILURE;

    if ((root = xmlDocGetRootElement(doc)) == NULL)
        return EXIT_FAILURE;

    print_elements(root);

    xmlFreeDoc(doc);
    xmlCleanupParser();

    return EXIT_SUCCESS;
}

测试：

$ cat test.xml
<commSyslog descr="Syslog Service" name="syslog" policyOwner="local" severity="critical">
<commSyslogClient adminState="disabled" forwardingFacility="local7" hostname="none" name="secondary" severity="critical"/>
<commSyslogClient adminState="disabled" forwardingFacility="local7" hostname="none" name="tertiary" severity="critical"/>
<commSyslogClient adminState="disabled" forwardingFacility="local7" hostname="none" name="primary" severity="critical"/>
<commSyslogMonitor adminState="disabled" descr="" name="" severity="critical"/>
<commSyslogConsole adminState="disabled" descr="" name="" severity="critical"/>
<commSyslogSource audits="disabled" descr="" events="disabled" faults="enabled" name=""/>
<commSyslogFile adminState="enabled" descr="" name="messages" severity="critical" size="4194304"/>
</commSyslog>

$ ./xmlkv test.xml
commSyslog.descr=Syslog Service
commSyslog.name=syslog
commSyslog.policyOwner=local
commSyslog.severity=critical
commSyslog.commSyslogClient[1].adminState=disabled
commSyslog.commSyslogClient[1].forwardingFacility=local7
commSyslog.commSyslogClient[1].hostname=none
commSyslog.commSyslogClient[1].name=secondary
commSyslog.commSyslogClient[1].severity=critical
commSyslog.commSyslogClient[2].adminState=disabled
commSyslog.commSyslogClient[2].forwardingFacility=local7
commSyslog.commSyslogClient[2].hostname=none
commSyslog.commSyslogClient[2].name=tertiary
commSyslog.commSyslogClient[2].severity=critical
commSyslog.commSyslogClient[3].adminState=disabled
commSyslog.commSyslogClient[3].forwardingFacility=local7
commSyslog.commSyslogClient[3].hostname=none
commSyslog.commSyslogClient[3].name=primary
commSyslog.commSyslogClient[3].severity=critical
commSyslog.commSyslogMonitor.adminState=disabled
commSyslog.commSyslogMonitor.descr=
commSyslog.commSyslogMonitor.name=
commSyslog.commSyslogMonitor.severity=critical
commSyslog.commSyslogConsole.adminState=disabled
commSyslog.commSyslogConsole.descr=
commSyslog.commSyslogConsole.name=
commSyslog.commSyslogConsole.severity=critical
commSyslog.commSyslogSource.audits=disabled
commSyslog.commSyslogSource.descr=
commSyslog.commSyslogSource.events=disabled
commSyslog.commSyslogSource.faults=enabled
commSyslog.commSyslogSource.name=
commSyslog.commSyslogFile.adminState=enabled
commSyslog.commSyslogFile.descr=
commSyslog.commSyslogFile.name=messages
commSyslog.commSyslogFile.severity=critical
commSyslog.commSyslogFile.size=4194304

看起来不错，正是我想要的。当然，将/ 替换为. 几乎没有用处，但我更喜欢这种表示法，因为它更好看。