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Diffstat (limited to 'nuttx/Documentation/NuttShell.html')
| -rw-r--r-- | nuttx/Documentation/NuttShell.html | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/nuttx/Documentation/NuttShell.html b/nuttx/Documentation/NuttShell.html index a2a4a7c5b..9418056eb 100644 --- a/nuttx/Documentation/NuttShell.html +++ b/nuttx/Documentation/NuttShell.html @@ -754,14 +754,50 @@ dd if=<infile> of=<outfile> [bs=<sectsize>] [count=<sectors </pre></ul> <p> <b>Synopsis</b>. - Copy blocks from <infile> to <outfile>. As an example: + Copy blocks from <infile> to <outfile>. + <infile> or <outfile> may be the path to a standard file, a character device, or a block device. + Examples follow: +</p> +<ol> + <li> + Read from character device, write to regular file. + This will create a new file of the specified size filled with zero. <ul><pre> +nsh> ls -l /dev +/dev: + crw-rw-rw- 0 zero nsh> dd if=/dev/zero of=/tmp/zeros bs=64 count=16 nsh> ls -l /tmp /tmp: -rw-rw-rw- 1024 ZEROS </pre></ul> -</p> + </li> + <li> + Read from character device, write to block device. + This will fill the entire block device with zeros. + </li> +<ul><pre> +nsh> ls -l /dev +/dev: + brw-rw-rw- 0 ram0 + crw-rw-rw- 0 zero +nsh> dd if=/dev/zero of=/dev/ram0 +</pre></ul> + </li> + <li> + Read from a block devic, write to a character device. This + will read the entire block device and dump the contents in + the bit bucket. + </li> +<ul><pre> +nsh> ls -l /dev +/dev: + crw-rw-rw- 0 null + brw-rw-rw- 0 ram0 +nsh> dd if=/dev/ram0 of=/dev/null +</pre></ul> + </li> +</ol> <table width ="100%"> <tr bgcolor="#e4e4e4"> |