\nA customer asked,\n“Given a hardlink name,\nis it possible to get the original file name used\nto create it in the first place?”\n<\/p>\n
\nRecall that hard links create an alternate name for a file.\nOnce that alternate name is created, there is no way to tell\nwhich is the original name and which is the new name.\nThe new file does not have a “link back to the original”;\nthey are both links to the underlying file content.\nThis is\n\nan old topic<\/a>,\nso I won’t go into further detail.\nThough this question does illustrate that many people\ncontinue to misunderstand what hard links are.\n<\/p>\n \nAnyway, once you figure out what the customer is actually asking,\nyou can give a meaningful answer:\n“Given the path to a file,\nhow can I get all the names\nby which the file can be accessed?”\nThe answer is\n \nNote that the names returned by the\n \nUpdate<\/b>: Minor errors corrected, as noted by\n\nacq<\/a> and\n\nAdrian<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" A customer asked, “Given a hardlink name, is it possible to get the original file name used to create it in the first place?” Recall that hard links create an alternate name for a file. Once that alternate name is created, there is no way to tell which is the original name and which is […]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[25],"class_list":["post-10103","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":" A customer asked, “Given a hardlink name, is it possible to get the original file name used to create it in the first place?” Recall that hard links create an alternate name for a file. Once that alternate name is created, there is no way to tell which is the original name and which is […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/10103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=10103"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/10103\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=10103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=10103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=10103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}FindFirstFileNameW<\/code>.\n<\/p>\nFindFirstFileNameW<\/code>\nfamily\nof functions are relative to the volume mount point.\nTo convert it to a full path, you need to append it to the mount point.\nSomething like this:\n<\/p>\n\ntypedef void (*ENUMERATEDNAMEPROC)(__in PCWSTR);\nvoid ProcessOneName(\n __in PCWSTR pszVolumeRoot,\n __in PCWSTR pszLink,\n __in ENUMERATEDNAMEPROC pfnCallback)\n{\n wchar_t szFile[MAX_PATH];\n if (SUCCEEDED(StringCchCopy(szFile, ARRAYSIZE(szFile), pszVolumeRoot)) &&\n PathAppend(szFile, pszLink)) {\n pfnCallback(szFile);\n }\n}\nvoid EnumerateAllNames(\n __in PCWSTR pszFileName,\n __in ENUMERATEDNAMEPROC pfnCallback)\n{\n \/\/ Supporting paths longer than MAX_PATH left as an exercise\n wchar_t szVolumeRoot[MAX_PATH];\n if (GetVolumePathName(pszFileName, szVolumeRoot, ARRAYSIZE(szVolumeRoot))) {\n wchar_t szLink[MAX_PATH];\n DWORD cchLink = ARRAYSIZE(szLink);\n HANDLE hFind = FindFirstFileNameW(pszFileName, 0, &cchLink, szLink);\n if (hFind != INVALID_HANDLE_VALUE) {\n ProcessOneName(szVolumeRoot, szLink, pfnCallback);\n while (cchLink = ARRAYSIZE(szLink),\n FindNextFileNameW(hFind, &cchLink, szLink)) {\n ProcessOneName(szVolumeRoot, szLink, pfnCallback);\n }\n FindClose(hFind);\n }\n }\n}\n\/\/ for demonstration purposes, we just print the name\nvoid PrintEachFoundName(__in PCWSTR pszFile)\n{\n _putws(pszFile);\n}\nint __cdecl wmain(int argc, wchar_t **argv)\n{\n for (int i = 1; i < argc; i++) {\n EnumerateAllNames(argv[i], PrintEachFoundName);\n }\n return 0;\n}\n<\/pre>\n