{
    "content": [
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            "text": "# extcheck(1) (man)\n\n**Summary:** extcheck - Detects version conflicts between a target Java Archive (JAR) file and currently installed extension JAR files.\n\n**Synopsis:** extcheck [options] targetfile.jar\noptions\nThe command-line options. See Options.\ntargetfile.jar\nThe target JAR file against which the currently installed extension JAR files are\ncompared to detect version conflicts.\n\n## Flags\n\n| Flag | Long | Arg | Description |\n|------|------|-----|-------------|\n| — | — | — | Lists JAR files in the extension directory as they are checked. Additionally, manifest attributes of the target JAR file |\n| — | — | — | Passes option to the Java Virtual Machine (JVM), where option is one of the options described on the reference page for  |\n\n## See Also\n\n- jar(1)\n\n## Section Outline\n\n- **NAME** (3 lines)\n- **SYNOPSIS** (10 lines)\n- **DESCRIPTION** (18 lines)\n- **OPTIONS** (1 lines) — 2 subsections\n  - -verbose (3 lines)\n  - -J_option_ (4 lines)\n- **SEE ALSO** (5 lines)\n\n## Full Content\n\n### NAME\n\nextcheck - Detects version conflicts between a target Java Archive (JAR) file and currently\ninstalled extension JAR files.\n\n### SYNOPSIS\n\nextcheck [options] targetfile.jar\n\n\noptions\nThe command-line options. See Options.\n\ntargetfile.jar\nThe target JAR file against which the currently installed extension JAR files are\ncompared to detect version conflicts.\n\n### DESCRIPTION\n\nThe extcheck command checks a specified JAR file for title and version conflicts with any\nextensions installed in the Java SE SDK. Before installing an extension, you can use this\nutility to see whether the same or a more recent version of the extension is already\ninstalled.\n\nThe extcheck command compares the Specification-title and Specification-version headers in\nthe manifest of the targetfile.jar file against the corresponding headers in all JAR files\ncurrently installed in the extension directory. By default, the extension directory is\njre/lib/ext on Oracle Solaris and \\jre\\lib\\ext on Windows. The extcheck command compares\nversion numbers in the same way as the java.lang.Package.isCompatibleWith method.\n\nIf no conflict is detected, then the return code is 0.\n\nIf the manifest of any JAR file in the extensions directory has the same Specification-title\nand the same or a newer Specification-version number, then a non-zero error code is returned.\nA non-zero error code is also returned when targetfile.jar does not have the Specification-\ntitle or Specification-version attributes in its manifest file.\n\n### OPTIONS\n\n#### -verbose\n\nLists JAR files in the extension directory as they are checked. Additionally, manifest\nattributes of the target JAR file and any conflicting JAR files are also reported.\n\n#### -J_option_\n\nPasses option to the Java Virtual Machine (JVM), where option is one of the options\ndescribed on the reference page for the Java launcher. For example, -J-Xms48m sets the\nstartup memory to 48 MB. See java(1).\n\n### SEE ALSO\n\n• jar(1)\n\n\n\nJDK 8                                     21 November 2013                               extcheck(1)\n\n"
        }
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    "structuredContent": {
        "command": "extcheck",
        "section": "1",
        "mode": "man",
        "summary": "extcheck - Detects version conflicts between a target Java Archive (JAR) file and currently installed extension JAR files.",
        "synopsis": "extcheck [options] targetfile.jar\noptions\nThe command-line options. See Options.\ntargetfile.jar\nThe target JAR file against which the currently installed extension JAR files are\ncompared to detect version conflicts.",
        "tldr_summary": null,
        "tldr_examples": [],
        "tldr_source": null,
        "flags": [
            {
                "flag": "",
                "long": null,
                "arg": null,
                "description": "Lists JAR files in the extension directory as they are checked. Additionally, manifest attributes of the target JAR file and any conflicting JAR files are also reported."
            },
            {
                "flag": "",
                "long": null,
                "arg": null,
                "description": "Passes option to the Java Virtual Machine (JVM), where option is one of the options described on the reference page for the Java launcher. For example, -J-Xms48m sets the startup memory to 48 MB. See java(1)."
            }
        ],
        "examples": [],
        "see_also": [
            {
                "name": "jar",
                "section": "1",
                "url": "https://www.chedong.com/phpMan.php/man/jar/1/json"
            }
        ],
        "section_outline": [
            {
                "name": "NAME",
                "lines": 3,
                "subsections": []
            },
            {
                "name": "SYNOPSIS",
                "lines": 10,
                "subsections": []
            },
            {
                "name": "DESCRIPTION",
                "lines": 18,
                "subsections": []
            },
            {
                "name": "OPTIONS",
                "lines": 1,
                "subsections": [
                    {
                        "name": "-verbose",
                        "lines": 3
                    },
                    {
                        "name": "-J_option_",
                        "lines": 4
                    }
                ]
            },
            {
                "name": "SEE ALSO",
                "lines": 5,
                "subsections": []
            }
        ]
    }
}