| 1 | //======================================================================== |
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| 2 | // |
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| 3 | // gbasename.cc |
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| 4 | // |
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| 5 | // Wrapper for libgen's basename() call which returns a std::string. |
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| 6 | // This is a convenience method working around questionable behavior |
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| 7 | // in the copy of basename() provided by libgen.h. |
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| 8 | // |
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| 9 | // According to man 3 basename: |
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| 10 | // |
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| 11 | // Both dirname() and basename() may modify the contents of path, so it |
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| 12 | // may be desirable to pass a copy when calling one of these functions. |
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| 13 | // |
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| 14 | // ... |
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| 15 | // |
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| 16 | // These functions may return pointers to statically allocated memory |
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| 17 | // which may be overwritten by subsequent calls. Alternatively, they |
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| 18 | // may return a pointer to some part of path, so that the string |
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| 19 | // referred to by path should not be modified or freed until the pointer |
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| 20 | // returned by the function is no longer required. |
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| 21 | // |
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| 22 | // Because basename can modify filename (for some reason), we have to |
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| 23 | // duplicate our input into a mutable buffer before we can call it. |
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| 24 | // The return value might be part of this mutable temporary, but not |
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| 25 | // generally the front, so 'char *' cannot be used as our return value. |
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| 26 | // The return value might also be a statically allocated string, |
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| 27 | // rendering basename (and thus gbasename) non-thread-safe. Because |
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| 28 | // we don't know how basename()'s return value is lifecycled, we need |
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| 29 | // to duplicate it again into something whose lifecycle we can predict. |
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| 30 | // |
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| 31 | // This is how a method that should amount to finding the last slash |
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| 32 | // in a string ends up requiring two memory allocations while managing |
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| 33 | // not to be thread-safe. In a way, it's kind of impressive. |
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| 34 | // |
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| 35 | // This file is licensed under the GPLv2 or later |
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| 36 | // |
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| 37 | // Copyright (C) 2018, 2019 Greg Knight <lyngvi@gmail.com> |
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| 38 | // Copyright (C) 2019 Albert Astals Cid <aacid@kde.org> |
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| 39 | // |
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| 40 | //======================================================================== |
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| 41 | |
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| 42 | #include "gbasename.h" |
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| 43 | #ifndef _MSC_VER |
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| 44 | # include <libgen.h> |
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| 45 | #endif |
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| 46 | #include <cstdlib> |
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| 47 | #include <cstring> |
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| 48 | |
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| 49 | std::string gbasename(const char *filename) |
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| 50 | { |
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| 51 | #ifdef _MSC_VER |
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| 52 | char fname[_MAX_FNAME] = {}, fext[_MAX_EXT] = {}; |
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| 53 | errno_t z = _splitpath_s(filename, NULL, 0, NULL, 0, fname, _countof(fname), fext, _countof(fext)); |
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| 54 | return std::string(fname) + std::string(fext); |
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| 55 | #else |
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| 56 | char *mutabl = strdup(s: filename); |
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| 57 | std::string retu = basename(path: mutabl); |
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| 58 | free(ptr: mutabl); |
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| 59 | return retu; |
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| 60 | #endif |
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| 61 | } |
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| 62 | |
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