projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 8c212ecf EA |
1 | ..From teklabs!ogcvax!root Tue Aug 3 05:14:38 1982 |
| 2 | ..TH DIRECTORY 3 "OGC Revision 8/02/82" | |
| 3 | .TH DIRECTORY 3X 8/1/82 | |
| 4 | .UC 4.1b Compatability | |
| 5 | .SH NAME | |
| 6 | opendir, readdir, telldir, seekdir, rewinddir, closedir \- flexible length directory operations | |
| 7 | .SH SYNOPSIS | |
| 8 | .B #include <dir.h> | |
| 9 | .PP | |
| 10 | .SM | |
| 11 | .B DIR | |
| 12 | .B *opendir(filename) | |
| 13 | .br | |
| 14 | .B char *filename; | |
| 15 | .PP | |
| 16 | .SM | |
| 17 | .B struct direct | |
| 18 | .B *readdir(dirp) | |
| 19 | .br | |
| 20 | .B DIR *dirp; | |
| 21 | .PP | |
| 22 | .SM | |
| 23 | .B long | |
| 24 | .B telldir(dirp) | |
| 25 | .br | |
| 26 | .B DIR *dirp; | |
| 27 | .PP | |
| 28 | .SM | |
| 29 | .B seekdir(dirp, loc) | |
| 30 | .br | |
| 31 | .B DIR *dirp; | |
| 32 | .br | |
| 33 | .B long loc; | |
| 34 | .PP | |
| 35 | .SM | |
| 36 | .B rewinddir(dirp) | |
| 37 | .br | |
| 38 | .B DIR *dirp; | |
| 39 | .PP | |
| 40 | .SM | |
| 41 | .B closedir(dirp) | |
| 42 | .br | |
| 43 | .B DIR *dirp; | |
| 44 | .PP | |
| 45 | .SM | |
| 46 | .B cc ... -lndir | |
| 47 | .SH DESCRIPTION | |
| 48 | The purpose of this library is to simulate | |
| 49 | the new flexible length directory names of 4.2bsd Unix | |
| 50 | on top of the old directory structure of 4.1bsd. | |
| 51 | It allows programs to be converted immediately | |
| 52 | to the new directory access interface, | |
| 53 | so that they need only be relinked | |
| 54 | when 4.2bsd becomes available. | |
| 55 | .PP | |
| 56 | .I opendir | |
| 57 | opens the directory named by | |
| 58 | .I filename | |
| 59 | and associates a | |
| 60 | .I directory stream | |
| 61 | with it. | |
| 62 | .I opendir | |
| 63 | returns a pointer to be used to identify the | |
| 64 | .I directory stream | |
| 65 | in subsequent operations. | |
| 66 | The pointer | |
| 67 | .SM | |
| 68 | .B NULL | |
| 69 | is returned if | |
| 70 | .I filename | |
| 71 | cannot be accessed or is not a directory. | |
| 72 | .PP | |
| 73 | .I readdir | |
| 74 | returns a pointer to the next directory entry. | |
| 75 | It returns | |
| 76 | .B NULL | |
| 77 | upon reaching the end of the directory or detecting | |
| 78 | an invalid | |
| 79 | .I seekdir | |
| 80 | operation. | |
| 81 | .PP | |
| 82 | .I telldir | |
| 83 | returns the current location associated with the named | |
| 84 | .I directory stream. | |
| 85 | .PP | |
| 86 | .I seekdir | |
| 87 | sets the position of the next | |
| 88 | .I readdir | |
| 89 | operation on the | |
| 90 | .I directory stream. | |
| 91 | The new position reverts to the one associated with the | |
| 92 | .I directory stream | |
| 93 | when the | |
| 94 | .I telldir | |
| 95 | operation was performed. | |
| 96 | Values returned by | |
| 97 | .I telldir | |
| 98 | are good only for the lifetime of the DIR pointer from | |
| 99 | which they are derived. | |
| 100 | If the directory is closed and then reopened, | |
| 101 | the | |
| 102 | .I telldir | |
| 103 | value may be invalidated | |
| 104 | due to undetected directory compaction. | |
| 105 | It is safe to use a previous | |
| 106 | .I telldir | |
| 107 | value immediately after a call to | |
| 108 | .I opendir | |
| 109 | and before any calls to | |
| 110 | .I readdir. | |
| 111 | .PP | |
| 112 | .I rewinddir | |
| 113 | resets the position of the named | |
| 114 | .I directory stream | |
| 115 | to the beginning of the directory. | |
| 116 | .PP | |
| 117 | .I closedir | |
| 118 | causes the named | |
| 119 | .I directory stream | |
| 120 | to be closed, | |
| 121 | and the structure associated with the DIR pointer to be freed. | |
| 122 | .PP | |
| 123 | See /usr/include/dir.h for a description of the fields available in | |
| 124 | a directory entry. | |
| 125 | The preferred way to search the current directory for entry "name" is: | |
| 126 | .br | |
| 127 | .sp | |
| 128 | len = strlen(name); | |
| 129 | .br | |
| 130 | dirp = opendir("."); | |
| 131 | .br | |
| 132 | for (dp = readdir(dirp); dp != NULL; dp = readdir(dir)) | |
| 133 | .br | |
| 134 | if (dp->d_namlen == len && !strcmp(dp->d_name, name)) { | |
| 135 | .br | |
| 136 | closedir(dirp); | |
| 137 | .br | |
| 138 | return FOUND; | |
| 139 | .br | |
| 140 | } | |
| 141 | .br | |
| 142 | closedir(dirp); | |
| 143 | .br | |
| 144 | return NOT_FOUND; | |
| 145 | .SH LINKING | |
| 146 | This library is accessed by specifying "-lndir" as the | |
| 147 | last argument to the compile line, e.g.: | |
| 148 | .br | |
| 149 | .sp | |
| 150 | cc -o prog prog.c -lndir | |
| 151 | .SH "SEE ALSO" | |
| 152 | /usr/include/dir.h, | |
| 153 | open(2), | |
| 154 | close(2), | |
| 155 | read(2), | |
| 156 | lseek(2) | |
| 157 | .SH AUTHOR | |
| 158 | Kirk McKusick. | |
| 159 | Report problems to mckusick@berkeley or ucbvax!mckusick. |