{"id":1865,"date":"2017-03-23T16:57:31","date_gmt":"2017-03-23T11:27:31","guid":{"rendered":"https:\/\/www.wikitechy.com\/technology\/?p=1865"},"modified":"2017-03-28T18:03:10","modified_gmt":"2017-03-28T12:33:10","slug":"can-find-broken-symlinks","status":"publish","type":"post","link":"https:\/\/www.wikitechy.com\/technology\/can-find-broken-symlinks\/","title":{"rendered":"[ Solved – 5 Answers ] PYTHON – How can you find broken symlinks"},"content":{"rendered":"

Is there a way to find all symbolic links that don\u2019t point anywere?<\/p>\n[pastacode lang=\u201dbash\u201d manual=\u201dfind%20.%2F%20-type%20l%0A\u201d message=\u201dBash Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n[ad type=\u201dbanner\u201d]\n

will give me all symbolic links, but makes no distinction between links that go somewhere and links that don\u2019t.<\/p>\n

You are currently doing:<\/p>\n[pastacode lang=\u201dpython\u201d manual=\u201dfind%20.%2F%20-type%20l%20-exec%20file%20%7B%7D%20%5C%3B%20%7Cgrep%20broken%0A\u201d message=\u201dPython Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n

The symlinks command can be used to identify symlinks with a variety of characteristics. For instance:<\/p>\n[pastacode lang=\u201dbash\u201d manual=\u201d%24%20rm%20a%0A%24%20ln%20-s%20a%20b%0A%24%20symlinks%20.%0Adangling%3A%20%2Ftmp%2Fb%20-%3E%20a%0A\u201d message=\u201dBash Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n

find -L can have unexpected consequence of expanding the search into symlinked directories, so isn\u2019t the optimal approach.<\/p>\n[pastacode lang=\u201dpython\u201d manual=\u201dfind%20%2Fpath%2Fto%2Fsearch%20-xtype%20l%0A\u201d message=\u201dPython Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n

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is the more concise, and logically identical command to<\/p>\n[pastacode lang=\u201dpython\u201d manual=\u201dfind%20%2Fpath%2Fto%2Fsearch%20-type%20l%20-xtype%20l%0A\u201d message=\u201dPython\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n

None of the solutions presented so far will detect cyclic symlinks, which is another type of breakage. this question addresses portability.
\nTo recap, the portable way to find broken symbolic links, including cyclic links, is:<\/p>\n[pastacode lang=\u201dpython\u201d manual=\u201dfind%20%2Fpath%2Fto%2Fsearch%20-type%20l%20-exec%20test%20!%20-e%20%7B%7D%20%5C%3B%20-print%0A\u201d message=\u201dPython Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n

To display a list of the broken links, replacing ${directory} with the desired root directory Edit<\/p>\n[pastacode lang=\u201dpython\u201d manual=\u201dfind%20%2Fpath%2Fto%2Fsearch%20-xtype%20l%0A%20%20%20%20%20%20for%20f%20in%20%24(find%20%2Fpath%2Fto%2Fsearch%20-type%20l)%3B%20do%20if%20%5B%20!%20-e%20%22%24f%22%20%5D%3B%20then%20echo%20%22%24f%22%3B%20fi%3B%20done%0A\u201d message=\u201dPython Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n

To display a list of the broken links,<\/p>\n[pastacode lang=\u201dpython\u201d manual=\u201dfind%20-xtype%20l%20-exec%20ls%20-l%20%7B%7D%20%5C%3B%0Afind%20%2Fusr%2Flocal%2Fbin%20-type%20l%20%7C%20while%20read%20f%3B%20do%20if%20%5B%20!%20-e%20%22%24f%22%20%5D%3B%20then%20ls%20-l%20%22%24f%22%3B%20fi%3B%20done%0A\u201d message=\u201dPython Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n

all one line, if there are broken links it will display them with ls -l<\/p>\n

This will print out the names of broken symlinks in the current directory.<\/p>\n[pastacode lang=\u201dpython\u201d manual=\u201dfor%20l%20in%20%24(find%20.%20-type%20l)%3B%20do%20cd%20%24(dirname%20%24l)%3B%20if%20%5B%20!%20-e%20%22%24(readlink%20%24(basename%20%24l))%22%20%5D%3B%0A%20%20%20%20%20%20%20%20%20then%20echo%20%20%20%24l%3B%20fi%3B%20cd%20-%20%3E%20%2Fdev%2Fnull%3B%20done%0A\u201d message=\u201dPython Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/]\n

Works in Bash.<\/p>\n

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Is there a way to find all symbolic links that don\u2019t point anywere? [pastacode lang=\u201dbash\u201d manual=\u201dfind%20.%2F%20-type%20l%0A\u201d message=\u201dBash Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/] [ad type=\u201dbanner\u201d] will give me all symbolic links, but makes no distinction between links that go somewhere and links that don\u2019t. You are currently doing: [pastacode lang=\u201dpython\u201d manual=\u201dfind%20.%2F%20-type%20l%20-exec%20file%20%7B%7D%20%5C%3B%20%7Cgrep%20broken%0A\u201d message=\u201dPython Code\u201d highlight=\u201d\u201d provider=\u201dmanual\u201d\/] SOLUTION 1: The […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4148],"tags":[3933,3942,3941,3943,3936,3934,3939,3931,3935,3937,3938,3940,3932],"class_list":["post-1865","post","type-post","status-publish","format-standard","hentry","category-python","tag-and-any-combination-thereof-leading-to-a-filedir","tag-how-can-i-relink-a-lot-of-broken-symlinks","tag-how-can-i-detect-whether-a-symlink-is-broken-in-bash","tag-how-do-i-tell-if-a-folder-is-actually-a-symlink-and-how-do-i-fix-it-if-its-broken","tag-how-to-find-dead-symbolic-links","tag-how-to-find-a-symlink-when-the-location-in-which-it-was-created-is-unknown","tag-how-to-grep-stderr","tag-how-to-prevent-find-execdir-from-following-symlinks","tag-how-would-i-find-any-symlinks-on-my-system-that-reference-tmp","tag-linux-find-broken-symlinks-with-python","tag-list-all-symbolic-links-to-valid-directories-only-with-find","tag-soft-link-detection","tag-thoroughly-find-all-links-hard-and-symlinks"],"_links":{"self":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/1865","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/comments?post=1865"}],"version-history":[{"count":0,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/1865\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/media?parent=1865"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/categories?post=1865"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/tags?post=1865"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}