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| author | Johannes Stoelp <johannes.stoelp@gmail.com> | 2025-04-13 21:31:18 +0200 |
|---|---|---|
| committer | Johannes Stoelp <johannes.stoelp@gmail.com> | 2025-04-13 21:31:18 +0200 |
| commit | 66c7f4cb944aea255f52fcb598c876b951879154 (patch) | |
| tree | 9cd12ee684b92a9e0a267607c4d14b99d2775230 | |
| parent | 5742a07bd78e0b815fe6f04eb48e47152e842a7b (diff) | |
| download | notes-66c7f4cb944aea255f52fcb598c876b951879154.tar.gz notes-66c7f4cb944aea255f52fcb598c876b951879154.zip | |
dd: initial notes
| -rw-r--r-- | src/SUMMARY.md | 1 | ||||
| -rw-r--r-- | src/cli/README.md | 1 | ||||
| -rw-r--r-- | src/cli/dd.md | 46 |
3 files changed, 48 insertions, 0 deletions
diff --git a/src/SUMMARY.md b/src/SUMMARY.md index ac41b1a..5af20c9 100644 --- a/src/SUMMARY.md +++ b/src/SUMMARY.md @@ -20,6 +20,7 @@ - [xargs](./cli/xargs.md) - [grep](./cli/grep.md) - [find](./cli/find.md) + - [dd](./cli/dd.md) - [Tools](./tools/README.md) - [tmux](./tools/tmux.md) diff --git a/src/cli/README.md b/src/cli/README.md index ffde988..2a115e3 100644 --- a/src/cli/README.md +++ b/src/cli/README.md @@ -12,3 +12,4 @@ - [xargs](./xargs.md) - [grep](./grep.md) - [find](./find.md) +- [dd](./dd.md) diff --git a/src/cli/dd.md b/src/cli/dd.md new file mode 100644 index 0000000..709cfa0 --- /dev/null +++ b/src/cli/dd.md @@ -0,0 +1,46 @@ +# dd(1) + +Copy data `block-wise`. + +``` +dd [opts] + if=<path> input file to read (stdin in case not specified) + of=<path> oputput file to write + status=progress show progress while copying + bs=<bytes> block size + count=<n> copy only <n> blocks + skip=<n> skip <n> blocks in input (seek input) + seek=<n> skip <n> blocks in oputput (seek output) + conv=<conv> + notrunc dont truncate output file + excl fail if output already exists + nocreat fail if output does not exists +``` + +## Example: bootstick + +```bash +dd bs=4M if=<iso> of=<blkdev> oflag=sync status=progress +``` + +## Example: patch file in place + +```bash +# Create a 1024 bytes file filled with zeros. +dd if=/dev/zero of=disk bs=512 count=2 + +# Overwrite 4 bytes starting at byte 0. +printf "aaaa" | dd of=disk bs=1 seek=0 conv=notrunc + +# Overwrite 4 bytes starting at byte 512. +printf "bbbb" | dd of=disk bs=1 seek=512 conv=notrunc + +hexdump disk +# 0000000 6161 6161 0000 0000 0000 0000 0000 0000 +# 0000010 0000 0000 0000 0000 0000 0000 0000 0000 +# * +# 0000200 6262 6262 0000 0000 0000 0000 0000 0000 +# 0000210 0000 0000 0000 0000 0000 0000 0000 0000 +# * +# 0000400 +``` |