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| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2012-07-30 14:40:27 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-30 17:25:14 -0700 |
| commit | 31550a16a5d2af859e8a11839e8c6c6c9c92dfa7 (patch) | |
| tree | b38c5921bfeecdfc24e3146b15e21360a490e19e /Documentation/printk-formats.txt | |
| parent | 3715c5309f6d175c3053672b73fd4f73be16fd07 (diff) | |
| download | lwn-31550a16a5d2af859e8a11839e8c6c6c9c92dfa7.tar.gz lwn-31550a16a5d2af859e8a11839e8c6c6c9c92dfa7.zip | |
vsprintf: add support of '%*ph[CDN]'
There are many places in the kernel where the drivers print small buffers
as a hex string. This patch adds a support of the variable width buffer
to print it as a hex string with a delimiter. The idea came from Pavel
Roskin here: http://www.digipedia.pl/usenet/thread/18835/17449/
Sample output of
pr_info("buf[%d:%d] %*phC\n", from, len, len, &buf[from]);
could be look like this:
[ 0.726130] buf[51:8] e8:16:b6:ef:e3:74:45:6e
[ 0.750736] buf[59:15] 31:81:b8:3f:35:49:06:ae:df:32:06:05:4a:af:55
[ 0.757602] buf[17:5] ac:16:d5:2c:ef
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/printk-formats.txt')
| -rw-r--r-- | Documentation/printk-formats.txt | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt index d8d168fa79d6..7561d7ed8e11 100644 --- a/Documentation/printk-formats.txt +++ b/Documentation/printk-formats.txt @@ -53,6 +53,16 @@ Struct Resources: For printing struct resources. The 'R' and 'r' specifiers result in a printed resource with ('R') or without ('r') a decoded flags member. +Raw buffer as a hex string: + %*ph 00 01 02 ... 3f + %*phC 00:01:02: ... :3f + %*phD 00-01-02- ... -3f + %*phN 000102 ... 3f + + For printing a small buffers (up to 64 bytes long) as a hex string with + certain separator. For the larger buffers consider to use + print_hex_dump(). + MAC/FDDI addresses: %pM 00:01:02:03:04:05 |