On Tue, Mar 25, 2014 at 08:24:13PM +0900, Kusanagi Kouichi wrote: > Description: > Bash's builtin printf cannot write more than one line to > /proc/pid/uid_map because printf writes one line at a time > and uid_map can be written only once.
Sounds like Bash is using the standard I/O library routines, in line buffering mode (i.e. setvbuf(..., _IOLBF, ...); ). It's not clear to me whether this can be considered a bug, as line-buffered output is common, and situations where it fails are rare. > Repeat-By: > # printf '0 0 1\n1 1 1' > /proc/31861/uid_map > printf: write error: Operation not permitted As a workaround, you might consider something like: printf '0 0 1\n1 1 1' | dd bs=1024 > /proc/31861/uid_map
