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Dmesg
dmesg (''diagnostic messages'') is a command on most Unix-like operating systems that prints the message buffer of the kernel. The output includes messages produced by the device drivers. Command On many Unix-like systems, the boot process generates a particularly dense stream of kernel messages. Many administrative issues pertain to whether a desired hardware device is successfully enumerated during the boot process, so the diagnostic process for a failed device often begins by inspecting the dmesg output from the kernel identification message to the point where the boot process concludes. Since this buffer can be overwritten by a flood of messages in subsequent operation, many Unix-like distributions store a post-boot copy of the message buffer at or similar secure system location. It is also common to manually consult the current dmesg buffer after hot-plugging devices, particularly USB devices (especially thumb drives), to determine whether the device has been recognized ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lsusb
lspci is a command on Unix-like operating systems that prints ("lists") detailed information about all PCI buses and devices in the system. It is based on a common portable library ''libpci'' which offers access to the PCI configuration space on a variety of operating systems. __TOC__ Example usage Example output on a Linux system: # lspci 00:00.0 Host bridge: Advanced Micro Devices, Inc. MDRaven/Raven2 Root Complex 00:00.2 IOMMU: Advanced Micro Devices, Inc. MDRaven/Raven2 IOMMU 00:01.0 Host bridge: Advanced Micro Devices, Inc. MDFamily 17h (Models 00h-1fh) PCIe Dummy Host Bridge 00:01.2 PCI bridge: Advanced Micro Devices, Inc. MDRaven/Raven2 PCIe GPP Bridge :000:01.7 PCI bridge: Advanced Micro Devices, Inc. MDRaven/Raven2 PCIe GPP Bridge :000:08.0 Host bridge: Advanced Micro Devices, Inc. MDFamily 17h (Models 00h-1fh) PCIe Dummy Host Bridge 00:08.1 PCI bridge: Advanced Micro Devices, Inc. MDRaven/Raven2 Internal PCIe GPP Bridge 0 to Bus A 00:14.0 SMBus: Advanced Mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lspci
lspci is a command on Unix-like operating systems that prints ("lists") detailed information about all PCI buses and devices in the system. It is based on a common portable library ''libpci'' which offers access to the PCI configuration space on a variety of operating systems. __TOC__ Example usage Example output on a Linux system: # lspci 00:00.0 Host bridge: Advanced Micro Devices, Inc. MDRaven/Raven2 Root Complex 00:00.2 IOMMU: Advanced Micro Devices, Inc. MDRaven/Raven2 IOMMU 00:01.0 Host bridge: Advanced Micro Devices, Inc. MDFamily 17h (Models 00h-1fh) PCIe Dummy Host Bridge 00:01.2 PCI bridge: Advanced Micro Devices, Inc. MDRaven/Raven2 PCIe GPP Bridge :000:01.7 PCI bridge: Advanced Micro Devices, Inc. MDRaven/Raven2 PCIe GPP Bridge :000:08.0 Host bridge: Advanced Micro Devices, Inc. MDFamily 17h (Models 00h-1fh) PCIe Dummy Host Bridge 00:08.1 PCI bridge: Advanced Micro Devices, Inc. MDRaven/Raven2 Internal PCIe GPP Bridge 0 to Bus A 00:14.0 SMBus: Advanced Mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like application is one that behaves like the corresponding Unix command or shell. Although there are general philosophies for Unix design, there is no technical standard defining the term, and opinions can differ about the degree to which a particular operating system or application is Unix-like. Some well-known examples of Unix-like operating systems include Linux and BSD. These systems are often used on servers, as well as on personal computers and other devices. Many popular applications, such as the Apache web server and the Bash shell, are also designed to be used on Unix-like systems. One of the key features of Unix-like systems is their ability to support multiple users and processes simultaneously. This allows users to run multipl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command-line Interface
A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and providing information to them as to what actions they are to perform. In some cases the invocation is conditional based on conditions established by the user or previous executables. Such access was first provided by computer terminals starting in the mid-1960s. This provided an interactive environment not available with punched cards or other input methods. Today, many users rely upon graphical user interfaces and menu-driven interactions. However, some programming and maintenance tasks may not have a graphical user interface and use a command line. Alternatives to the command-line interface include text-based user interface menus (for example, IBM AIX SMIT), keyboard shortcuts, and various desktop metaphors centered on the pointer (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syslog
In computing, syslog is a standard for message logging. It allows separation of the software that generates messages, the system that stores them, and the software that reports and analyzes them. Each message is labeled with a facility code, indicating the type of system generating the message, and is assigned a severity level. Computer system designers may use syslog for system management and security auditing as well as general informational, analysis, and debugging messages. A wide variety of devices, such as printers, routers, and message receivers across many platforms use the syslog standard. This permits the consolidation of logging data from different types of systems in a central repository. Implementations of syslog exist for many operating systems. When operating over a network, syslog uses a client-server architecture where a syslog server listens for and logs messages coming from clients. History Syslog was developed in the 1980s by Eric Allman as part of the Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grep
grep is a command-line utility for searching plain-text data sets for lines that match a regular expression. Its name comes from the ed command ''g/re/p'' (''globally search for a regular expression and print matching lines''), which has the same effect. grep was originally developed for the Unix operating system, but later available for all Unix-like systems and some others such as OS-9. History Before it was named, grep was a private utility written by Ken Thompson to search files for certain patterns. Doug McIlroy, unaware of its existence, asked Thompson to write such a program. Responding that he would think about such a utility overnight, Thompson actually corrected bugs and made improvements for about an hour on his own program called s (short for "search"). The next day he presented the program to McIlroy, who said it was exactly what he wanted. Thompson's account may explain the belief that grep was written overnight. Thompson wrote the first version in PDP-11 assembly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Less (Unix)
less is a terminal pager Computer program, program on Unix, Microsoft Windows, Windows, and Unix-like systems used to view (but not change) the contents of a text file one screen at a time. It is similar to , but has the extended capability of allowing both forward and backward navigation through the file. Unlike most Unix text editors/viewers, does not need to read the entire file before starting, allowing for immediate viewing regardless of file size. History Mark Nudelman initially wrote less during 1983–85, in the need of a version of More (command), more able to do backward scrolling of the displayed text. The name came from the joke of doing "backwards more." Originally, less was developed for Unix, but it has been ported to a number of other operating systems, including MS-DOS, Microsoft Windows, OS/2, and OS-9, as well as Unix-like systems such as Linux. It is still maintained today by Nudelman. To help remember the difference between less and more, a common joke is to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tail (Unix)
tail is a program available on Unix, Unix-like systems, FreeDOS and MSX-DOS used to display the tail end of a text file or piped data. Implementations The version of tail bundled in GNU coreutils was written by Paul Rubin, David MacKenzie, Ian Lance Taylor, and Jim Meyering. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. The FreeDOS version was developed by M. Aitchison. A tail command is also part of ASCII's ''MSX-DOS2 Tools'' for MSX-DOS version 2. ''CCZE'' is tail-like while displaying its output in color. ''pctail'' is similar to CCZE. It is a colorized tail programmed in Python which tails and colorizes syslog output. ''Inotail'' is a deprecated implementation of inotify kernel interface. The early implementation of tail polled every second to see if new data can be displayed, as tail implemented inotifiy kernel interface Inotail become deprecated and it is not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
More (command)
In computing, more is a command to view (but not modify) the contents of a text file one screen at a time. It is available on Unix and Unix-like systems, DOS, Digital Research FlexOS, IBM/Toshiba 4690 OS, IBM OS/2, Microsoft Windows and ReactOS. Programs of this sort are called ''pagers''. more is a very basic pager, originally allowing only forward navigation through a file, though newer implementations do allow for limited backward movement. History The more command was originally written by Daniel Halbert, a graduate student at the University of California, Berkeley, in 1978. It was later expanded on by Eric Shienbrood, Geoff Peck (added underlining, single spacing) and John Foderaro (added -c, more environment variable history). It was first included in 3.0 BSD, and has since become a standard program in all Unix systems. less, a similar command with the extended capability of allowing both forward and backward navigation through the file, was written by Mark Nudelman betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clocksource On Linux Booting Screenshot
A real-time clock (RTC) is an electronic device (most often in the form of an integrated circuit) that measures the passage of time. Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are present in almost any electronic device which needs to keep accurate time of day. Terminology The term ''real-time clock'' is used to avoid confusion with ordinary hardware clocks which are only signals that govern digital electronics, and do not count time in human units. RTC should not be confused with real-time computing, which shares its three-letter acronym but does not directly relate to time of day. Purpose Although keeping time can be done without an RTC, using one has benefits: * Low power consumption (important when running from alternate power) * Frees the main system for time-critical tasks * Sometimes more accurate than other methods A GPS receiver can shorten its startup time by comparing the current time, according to its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Console
One meaning of system console, computer console, root console, computer operator, operator's console, or simply console is the text entry and display device for system administration messages, particularly those from the BIOS or boot loader, the Kernel (computer science), kernel, from the init system and from the syslog, system logger. It is a physical device consisting of a keyboard and a screen, and traditionally is a text terminal, but may also be a graphical terminal. System consoles are generalized to computer terminals, which are abstracted respectively by virtual consoles and terminal emulators. Today communication with system consoles is generally done abstractly, via the standard streams (stdin, stdout, and stderr), but there may be system-specific interfaces, for example those used by the system kernel. Another, older, meaning of system console, computer console, hardware console, operator's console or simply console is a hardware component used by an operator to control ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Serial Bus
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad variety of USB hardware exists, including 14 different connector types, of which USB-C is the most recent and the only one not currently deprecated. First released in 1996, the USB standards are maintained by the USB Implementers Forum (USB-IF). The four generations of USB are: USB 1.''x'', USB 2.0, USB 3.''x'', and USB4. Overview USB was designed to standardize the connection of peripherals to personal computers, both to communicate with and to supply electric power. It has largely replaced interfaces such as serial ports and parallel ports, and has become commonplace on a wide range of devices. Examples of peripherals that are connected via USB include computer keyboards and mice, video cameras, printers, portable media players, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
