Red Hat LINUX 7.2 Reference Manual page 63

Section 4.2:Top-Level Files in /proc
When the same machine is unplugged from its power source and running on its own batteries for a
few minutes, you will see the contents of the apm file change:
1.14 1.2 0x03 0x00 0x00 0x01 99% 1792 min
In this state, the apm command yields readable information from this data:
[ed@blink /]$ apm -v
APM BIOS 1.2 (kernel driver 1.14)
AC off-line, battery status high: 99% (1 day, 5:52)
[ed@blink /]$
This demonstrates the connection between data located in raw /proc files and the utilities designed
to use that information for specific purposes.
4.2.2 /proc/cmdline
This file essentially shows the parameters passed to the Linux kernel at the time it is started. A sample
/proc/cmdline file looks similar to this:
auto BOOT_IMAGE=linux ro root=305 BOOT_FILE=/boot/vmlinuz-2.4.2-2
The important data contained in the file breaks down in the following way:
• BOOT_IMAGE=linux, which tells you the name of the image used to boot the machine.
• ro, which signifies that the kernel is loaded read-only.
• BOOT_FILE=/boot/vmlinuz-2.4.2-2 notes the actual Linux kernel file used to boot the
system.
4.2.3 /proc/cpuinfo
This file changes based on the type of processor in your system. The output is fairly easy to understand.
A sample file looks like this:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 6
model name : Celeron (Mendocino)
stepping : 0
cpu MHz : 334.099
cache size : 128 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
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