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author | Ingo Molnar <mingo@elte.hu> | 2008-12-16 22:04:48 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-12-16 22:04:48 +0100 |
commit | 78f902ccc597d6ce3e8d1477d70f2d79e960ba7a (patch) | |
tree | c6ceab663de16501d1dda1c1596fe2dacaaef8e3 /Documentation/printk-formats.txt | |
parent | 9ee670fd87b7d69c8633b94c42aadcbbcb96f28e (diff) | |
parent | 8b1fae4e4200388b64dd88065639413cb3f1051c (diff) |
Merge commit 'v2.6.28-rc8' into x86/doc
Diffstat (limited to 'Documentation/printk-formats.txt')
-rw-r--r-- | Documentation/printk-formats.txt | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt new file mode 100644 index 00000000000..1b5a5ddbc3e --- /dev/null +++ b/Documentation/printk-formats.txt @@ -0,0 +1,35 @@ +If variable is of Type, use printk format specifier: +--------------------------------------------------------- + int %d or %x + unsigned int %u or %x + long %ld or %lx + unsigned long %lu or %lx + long long %lld or %llx + unsigned long long %llu or %llx + size_t %zu or %zx + ssize_t %zd or %zx + +Raw pointer value SHOULD be printed with %p. + +u64 SHOULD be printed with %llu/%llx, (unsigned long long): + + printk("%llu", (unsigned long long)u64_var); + +s64 SHOULD be printed with %lld/%llx, (long long): + + printk("%lld", (long long)s64_var); + +If <type> is dependent on a config option for its size (e.g., sector_t, +blkcnt_t, phys_addr_t, resource_size_t) or is architecture-dependent +for its size (e.g., tcflag_t), use a format specifier of its largest +possible type and explicitly cast to it. Example: + + printk("test: sector number/total blocks: %llu/%llu\n", + (unsigned long long)sector, (unsigned long long)blockcount); + +Reminder: sizeof() result is of type size_t. + +Thank you for your cooperation and attention. + + +By Randy Dunlap <rdunlap@xenotime.net> |