93 lines
2.0 KiB
C
93 lines
2.0 KiB
C
/*-------------------------------------------------------------------------
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*
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* pgcheckdir.c
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*
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* A simple subroutine to check whether a directory exists and is empty or not.
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* Useful in both initdb and the backend.
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*
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* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* src/port/pgcheckdir.c
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*-------------------------------------------------------------------------
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*/
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#include "c.h"
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#include <dirent.h>
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/*
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* Test to see if a directory exists and is empty or not.
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*
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* Returns:
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* 0 if nonexistent
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* 1 if exists and empty
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* 2 if exists and contains _only_ dot files
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* 3 if exists and contains a mount point
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* 4 if exists and not empty
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* -1 if trouble accessing directory (errno reflects the error)
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*/
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int
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pg_check_dir(const char *dir)
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{
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int result = 1;
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DIR *chkdir;
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struct dirent *file;
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bool dot_found = false;
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bool mount_found = false;
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int readdir_errno;
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chkdir = opendir(dir);
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if (chkdir == NULL)
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return (errno == ENOENT) ? 0 : -1;
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while (errno = 0, (file = readdir(chkdir)) != NULL)
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{
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if (strcmp(".", file->d_name) == 0 ||
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strcmp("..", file->d_name) == 0)
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{
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/* skip this and parent directory */
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continue;
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}
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#ifndef WIN32
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/* file starts with "." */
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else if (file->d_name[0] == '.')
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{
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dot_found = true;
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}
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/* lost+found directory */
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else if (strcmp("lost+found", file->d_name) == 0)
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{
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mount_found = true;
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}
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#endif
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else
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{
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result = 4; /* not empty */
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break;
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}
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}
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if (errno)
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result = -1; /* some kind of I/O error? */
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/* Close chkdir and avoid overwriting the readdir errno on success */
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readdir_errno = errno;
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if (closedir(chkdir))
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result = -1; /* error executing closedir */
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else
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errno = readdir_errno;
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/* We report on mount point if we find a lost+found directory */
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if (result == 1 && mount_found)
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result = 3;
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/* We report on dot-files if we _only_ find dot files */
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if (result == 1 && dot_found)
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result = 2;
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return result;
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}
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