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| 28 | .\" @(#)mknod.2 8.1 (Berkeley) 6/4/93 |
| 29 | .\" $FreeBSD: src/lib/libc/sys/mknod.2,v 1.18 2008/04/16 13:03:12 kib Exp $ |
| 30 | .\" |
| 31 | .Dd August 6, 2010 |
| 32 | .Dt MKNOD 2 |
| 33 | .Os |
| 34 | .Sh NAME |
| 35 | .Nm mknod , |
| 36 | .Nm mknodat |
| 37 | .Nd make a special file node |
| 38 | .Sh LIBRARY |
| 39 | .Lb libc |
| 40 | .Sh SYNOPSIS |
| 41 | .In sys/stat.h |
| 42 | .Ft int |
| 43 | .Fn mknod "const char *path" "mode_t mode" "dev_t dev" |
| 44 | .Ft int |
| 45 | .Fn mknodat "int fd" "const char *path" "mode_t mode" "dev_t dev" |
| 46 | .Sh DESCRIPTION |
| 47 | The file system node |
| 48 | .Fa path |
| 49 | is created with the file type and access permissions specified in |
| 50 | .Fa mode . |
| 51 | The access permissions are modified by the process's umask value. |
| 52 | .Pp |
| 53 | If |
| 54 | .Fa mode |
| 55 | indicates a block or character special file, |
| 56 | .Fa dev |
| 57 | is a configuration dependent specification denoting a particular device |
| 58 | on the system. |
| 59 | Otherwise, |
| 60 | .Fa dev |
| 61 | is ignored. |
| 62 | .Pp |
| 63 | The |
| 64 | .Fn mknod |
| 65 | system call |
| 66 | requires super-user privileges. |
| 67 | .Pp |
| 68 | The |
| 69 | .Fn mknodat |
| 70 | system call is equivalent to |
| 71 | .Fn mknod |
| 72 | except in the case where |
| 73 | .Fa path |
| 74 | specifies a relative path. |
| 75 | In this case the newly created device node is created relative to the |
| 76 | directory associated with the file descriptor |
| 77 | .Fa fd |
| 78 | instead of the current working directory. |
| 79 | If |
| 80 | .Fn mknodat |
| 81 | is passed the special value |
| 82 | .Dv AT_FDCWD |
| 83 | in the |
| 84 | .Fa fd |
| 85 | parameter, the current working directory is used and the behavior is |
| 86 | identical to a call to |
| 87 | .Fn mknod . |
| 88 | .Sh RETURN VALUES |
| 89 | .Rv -std mknod |
| 90 | .Sh ERRORS |
| 91 | The |
| 92 | .Fn mknod |
| 93 | system call |
| 94 | will fail and the file will be not created if: |
| 95 | .Bl -tag -width Er |
| 96 | .It Bq Er ENOTDIR |
| 97 | A component of the path prefix is not a directory. |
| 98 | .It Bq Er ENAMETOOLONG |
| 99 | A component of a pathname exceeded 255 characters, |
| 100 | or an entire path name exceeded 1023 characters. |
| 101 | .It Bq Er ENOENT |
| 102 | A component of the path prefix does not exist. |
| 103 | .It Bq Er EACCES |
| 104 | Search permission is denied for a component of the path prefix. |
| 105 | .It Bq Er ELOOP |
| 106 | Too many symbolic links were encountered in translating the pathname. |
| 107 | .It Bq Er EPERM |
| 108 | The process's effective user ID is not super-user. |
| 109 | .It Bq Er EIO |
| 110 | An I/O error occurred while making the directory entry or allocating the inode. |
| 111 | .It Bq Er ENOSPC |
| 112 | The directory in which the entry for the new node is being placed |
| 113 | cannot be extended because there is no space left on the file |
| 114 | system containing the directory. |
| 115 | .It Bq Er ENOSPC |
| 116 | There are no free inodes on the file system on which the |
| 117 | node is being created. |
| 118 | .It Bq Er EDQUOT |
| 119 | The directory in which the entry for the new node |
| 120 | is being placed cannot be extended because the |
| 121 | user's quota of disk blocks on the file system |
| 122 | containing the directory has been exhausted. |
| 123 | .It Bq Er EDQUOT |
| 124 | The user's quota of inodes on the file system on |
| 125 | which the node is being created has been exhausted. |
| 126 | .It Bq Er EROFS |
| 127 | The named file resides on a read-only file system. |
| 128 | .It Bq Er EEXIST |
| 129 | The named file exists. |
| 130 | .It Bq Er EFAULT |
| 131 | The |
| 132 | .Fa path |
| 133 | argument |
| 134 | points outside the process's allocated address space. |
| 135 | .It Bq Er EINVAL |
| 136 | Creating anything else than a block or character special |
| 137 | file (or a |
| 138 | .Em whiteout ) |
| 139 | is not supported. |
| 140 | .El |
| 141 | .Pp |
| 142 | In addition to the errors returned by the |
| 143 | .Fn mknod , |
| 144 | the |
| 145 | .Fn mknodat |
| 146 | may fail if: |
| 147 | .Bl -tag -width Er |
| 148 | .It Bq Er EBADF |
| 149 | The |
| 150 | .Fa path |
| 151 | argument does not specify an absolute path and the |
| 152 | .Fa fd |
| 153 | argument is neither |
| 154 | .Dv AT_FDCWD |
| 155 | nor a valid file descriptor open for searching. |
| 156 | .It Bq Er ENOTDIR |
| 157 | The |
| 158 | .Fa path |
| 159 | argument is not an absolute path and |
| 160 | .Fa fd |
| 161 | is neither |
| 162 | .Dv AT_FDCWD |
| 163 | nor a file descriptor associated with a directory. |
| 164 | .El |
| 165 | .Sh SEE ALSO |
| 166 | .Xr chmod 2 , |
| 167 | .Xr mkfifo 2 , |
| 168 | .Xr stat 2 , |
| 169 | .Xr umask 2 |
| 170 | .Sh STANDARDS |
| 171 | The |
| 172 | .Fn mknodat |
| 173 | system call follows The Open Group Extended API Set 2 specification. |
| 174 | .Sh HISTORY |
| 175 | The |
| 176 | .Fn mknod |
| 177 | function appeared in |
| 178 | .At v6 . |
| 179 | The |
| 180 | .Fn mknodat |
| 181 | system call appeared in |
| 182 | .Dx 2.7 . |