3 cons \- console, clocks, process/process group ids, user, null, reboot, etc.
33 The console device serves a one-level directory
34 giving access to the console screen and
35 miscellaneous information.
43 causes the characters to be printed on the console screen. Console
44 input is handled by a different program (see
49 file contains a textual representation of the operating system's version and parameters.
50 At the moment, it contains one field: the 9P protocol version, currently
55 file contains a copy of the kernel configuration file used to build the kernel.
59 file holds the last 16 kilobytes of output written to the console
60 by the kernel's print statements or by processes writing to
62 It is useful for retrieving boot messages once the boot
67 file may be read to receive a copy of the data written
68 to the console by the kernel's print statements or by processes
71 Only data written after the file is opened is available.
72 If the machine's console is a serial line, the data is sent both to the
75 if its console is a graphics screen, the data is sent either to the
79 (It is advisable not to open
81 on terminals until you have started
86 file throws away anything written to it
87 and always returns zero when read.
91 file is a read-only file that produces an infinite stream of zero-valued bytes when read.
95 file contains, one per line, a listing of the drivers configured in the kernel, in the format
103 file contains the name of the authentication domain that
104 this host belongs to; see
106 Only the user named in
112 file contains the name of the user that owns the console device files.
113 The hostowner also has group permissions for any local devices.
117 return a stream of random bytes produced by the kernels cryptographic
118 random number generator. The rate at which data can be read depends on
119 the implementation and can vary from hundreds of megabytes to just
120 a few hundred bits a second. Therefore,
122 should be treated as a seed to
123 pseudo-random number generators which can produce a faster
130 causes the system to shutdown and, if
135 loads the named kernel image and restarts,
136 preserving the kernel configuration in
144 activates the remote kernel debugger (see
147 owner has the ability to open this file.
150 is a binary interface that provides
151 the same information as
155 and also controls clock frequency and clock trim.
156 All integers read or written from
158 are in big endian order.
159 Unlike the other files, reads and writes do not affect
160 the offset. Therefore, there is no need for a seek
161 back to zero between subsequent accesses.
164 returns 24 bytes, three 8 byte numbers, representing nanoseconds
165 since start of epoch, clock ticks, and clock frequency.
169 is a message with one of 3 formats:
170 .IP "\f5n\fP<8-byte \f2time\fP>" 1.2i
171 set the nanoseconds since epoch to the given
173 .IP "\f5d\fP<8-byte \f2delta\fP><4-byte \f2period\fP>" 1.2i
174 trim the nanoseconds since epoch by
179 .IP "\f5f\fP<8-byte \f2freq\fP>" 1.2i
180 Set the frequency for interpreting clock ticks to be
184 The rest of the files contain (mostly) read-only strings.
185 Each string has a fixed length: a
187 of more than that gives a result of that fixed length (the result does not
188 include a terminating zero byte);
191 of less than that length leaves the file offset so the
192 rest of the string (but no more) will be read the next time.
193 To reread the file without closing it,
195 must be used to reset the offset.
196 When the file contains numeric data
197 each number is formatted in decimal.
198 If the binary number fits in 32 bits, it is formatted as an
199 11 digit decimal number with
200 leading blanks and one trailing blank; totaling 12 bytes.
202 is formatted as 21 digit decimal numbers with leading blanks and one
203 trailing blank; totaling 22 bytes.
207 file holds six 32-bit numbers, containing the time in milliseconds
208 that the current process has spent in user mode, system calls,
209 real elapsed time, and then the time spent, by exited children and their descendants,
210 in user mode, system calls, and real elapsed time.
214 file holds one 32-bit number representing the seconds since start of epoch
215 and three 64-bit numbers, representing nanoseconds since
216 start of epoch, clock ticks, and clock frequency.
218 A write of a decimal number to
220 will set the seconds since epoch.
224 file holds the textual name of the machine, e.g.
230 file holds 10 numbers:
231 processor number, context switches, interrupts, system calls, page faults,
232 TLB faults, TLB purges, load average, idle time and time spent servicing interrupts.
233 The load average is in units of milli-CPUs and is decayed over time;
234 idle time and interrupt time are percentage units;
235 the others are total counts from boot time.
236 If the machine is a multiprocessor,
238 holds one line per processor.
241 resets all of the counts on all processors.
245 device holds a text block giving memory usage statistics:
253 \fIa\fP/\fIn\fP/\fIm\fP kernel malloc
254 \fIa\fP/\fIn\fP/\fIm\fP kernel draw
257 These are total memory (bytes), system page size (bytes),
258 kernel memory (pages), user memory (pages), swap space (pages),
259 kernel malloced data (bytes), and kernel graphics data (bytes).
267 For kernel malloc and kernel draw,
269 indicates the current allocation in bytes.
270 These numbers are not blank padded.
272 To turn on swapping, write to
274 the textual file descriptor number of a file or device on which to swap.
280 will inevitably cause the front to fall off.
282 The other files served by the
284 device are all single numbers:
293 parent's process number
303 .B /sys/src/9/port/devcons.c