Red Hat ENTERPRISE LINUX 3 Reference Manual

Also see for ENTERPRISE LINUX 3 - SECURITY GUIDE: Tuning guide Installation guide Installation guide Installation guide Manual

Contents

Chapter 5. The proc File System 475.2.1. /proc/apmThis file provides information about the state of the Advanced Power Management (APM) system andis used by the apm command. If a system with no battery is connected to an AC power source, thisvirtual file would look similar to the following:1.16 1.2 0x07 0x01 0xff 0x80 -1% -1 ?Running the apm -v command on such a system results in output similar to the following:APM BIOS 1.2 (kernel driver 1.16)AC on-line, no system batteryFor systems which do not use a battery as a power source, apm is able do little more than put themachine in standby mode. The apm command is much more useful on laptops. For example, thefollowing output is from the command cat /proc/apm on a laptop while plugged into a poweroutlet:1.16 1.2 0x03 0x01 0x03 0x09 100% -1 ?When the same laptop is unplugged from its power source for a few minutes, the contents of the apmfile change to something like the following:1.16 1.2 0x03 0x00 0x00 0x01 99% 1792 minThe apm -v command now yields more useful data, such as the following:APM BIOS 1.2 (kernel driver 1.16)AC off-line, battery status high: 99% (1 day, 5:52)5.2.2. /proc/cmdlineThis file shows the parameters passed to the kernel at the time it is started. A sample /proc/cmdlinefile looks like the following:ro root=/dev/hda2This tells us that the kernel is mounted read-only (signified by (ro)) off of the second partition onthe first IDE device (/dev/hda2).5.2.3. /proc/cpuinfoThis virtual file identifies the type of processor used by your system. The following is an example ofthe output typical of /proc/cpuinfo:processor : 0vendor_id : GenuineIntelcpu family : 15model : 2model name : Intel(R) Xeon(TM) CPU 2.40GHzstepping : 7cpu MHz : 2392.371cache size : 512 KBphysical id : 0siblings : 2