src/common/pgfnames.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pgfnames.c
   4  *        directory handling functions
   5  *
   6  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * IDENTIFICATION
  10  *        src/common/pgfnames.c
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14
  15 #ifndef FRONTEND
  16 #include "postgres.h"
  17 #else
  18 #include "postgres_fe.h"
  19 #endif
  20
  21 #include <dirent.h>
  22
  23 #ifndef FRONTEND
  24 #define pg_log_warning(...) elog(WARNING, __VA_ARGS__)
  25 #else
  26 #include "common/logging.h"
  27 #endif
  28
  29 /*
  30  * pgfnames
  31  *
  32  * return a list of the names of objects in the argument directory.  Caller
  33  * must call pgfnames_cleanup later to free the memory allocated by this
  34  * function.
  35  */
  36 char      **
  37 pgfnames(const char *path)
  38 {
  39         DIR                *dir;
  40         struct dirent *file;
  41         char      **filenames;
  42         int                     numnames = 0;
  43         int                     fnsize = 200;   /* enough for many small dbs */
  44
  45         dir = opendir(path);
  46         if (dir == NULL)
  47         {
  48                 pg_log_warning("could not open directory \"%s\": %m", path);
  49                 return NULL;
  50         }
  51
  52         filenames = (char **) palloc(fnsize * sizeof(char *));
  53
  54         while (errno = 0, (file = readdir(dir)) != NULL)
  55         {
  56                 if (strcmp(file->d_name, ".") != 0 && strcmp(file->d_name, "..") != 0)
  57                 {
  58                         if (numnames + 1 >= fnsize)
  59                         {
  60                                 fnsize *= 2;
  61                                 filenames = (char **) repalloc(filenames,
  62                                                                                            fnsize * sizeof(char *));
  63                         }
  64                         filenames[numnames++] = pstrdup(file->d_name);
  65                 }
  66         }
  67
  68         if (errno)
  69                 pg_log_warning("could not read directory \"%s\": %m", path);
  70
  71         filenames[numnames] = NULL;
  72
  73         if (closedir(dir))
  74                 pg_log_warning("could not close directory \"%s\": %m", path);
  75
  76         return filenames;
  77 }
  78
  79
  80 /*
  81  *      pgfnames_cleanup
  82  *
  83  *      deallocate memory used for filenames
  84  */
  85 void
  86 pgfnames_cleanup(char **filenames)
  87 {
  88         char      **fn;
  89
  90         for (fn = filenames; *fn; fn++)
  91                 pfree(*fn);
  92
  93         pfree(filenames);
  94 }