85 lines
1.4 KiB
C++
85 lines
1.4 KiB
C++
#include <dirent.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <sys/syscall.h>
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#include <unistd.h>
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struct __DIR
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{
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int fd { -1 };
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size_t entry_count { 0 };
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size_t entry_index { 0 };
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// FIXME: we should probably allocate entries dynamically
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// based if syscall returns ENOBUFS
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dirent entries[128];
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};
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int closedir(DIR* dirp)
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{
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if (dirp == nullptr || dirp->fd == -1)
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{
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errno = EBADF;
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return -1;
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}
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close(dirp->fd);
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free(dirp);
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return 0;
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}
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int dirfd(DIR* dirp)
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{
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if (dirp == nullptr || dirp->fd == -1)
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{
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errno = EINVAL;
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return -1;
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}
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return dirp->fd;
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}
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DIR* fdopendir(int fd)
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{
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DIR* dirp = (DIR*)malloc(sizeof(DIR));
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if (dirp == nullptr)
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return nullptr;
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dirp->fd = fd;
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dirp->entry_count = 0;
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dirp->entry_index = 0;
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return dirp;
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}
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DIR* opendir(const char* dirname)
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{
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int fd = open(dirname, O_RDONLY);
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if (fd == -1)
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return nullptr;
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return fdopendir(fd);
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}
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struct dirent* readdir(DIR* dirp)
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{
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if (dirp == nullptr || dirp->fd == -1)
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{
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errno = EBADF;
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return nullptr;
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}
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dirp->entry_index++;
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if (dirp->entry_index < dirp->entry_count)
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return &dirp->entries[dirp->entry_index];
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long entry_count = syscall(SYS_READ_DIR, dirp->fd, dirp->entries, sizeof(dirp->entries) / sizeof(dirp->entries[0]));
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if (entry_count <= 0)
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return nullptr;
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dirp->entry_count = entry_count;
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dirp->entry_index = 0;
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return &dirp->entries[0];
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}
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