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Util-linux-ng
is a standard package distributed by the Linux Kernel Organization for use as part of the Linux operating system. A fork, (with meaning "next generation"), was created when development stalled, but has been renamed back to , and is the official version of the package. Contents Included It includes the following utilities: Removed Utilities formerly included, but removed : * arch * chkdupexe * clock * cytune * ddate (removed from default build before being removed altogether) * elvtune * fastboot * fasthalt * halt * initctl * ramsize (formerly a symlink to rdev) * rdev * reboot * rootflags (formerly a symlink to rdev) * shutdown * simpleinit * tailf * vidmode (formerly a symlink to rdev) See also * BusyBox * cat (Unix) * CUPS * GNU Core Utilities * Toybox * uname References External links The util-linux code repository.pub/linux/utils/util-linuxon Kernel.org kernel.org is the main distribution point of source code for the Linux kernel, which is the base of the Linux ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced like the letter c'') is a General-purpose language, general-purpose computer programming language. It was created in the 1970s by Dennis Ritchie, and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted CPUs. It has found lasting use in operating systems, device drivers, protocol stacks, though decreasingly for application software. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the measuring programming language popularity, most widely used programming languages, with C compilers avail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Locking
File locking is a mechanism that restricts access to a computer file, or to a region of a file, by allowing only one user or process to modify or delete it at a specific time and to prevent reading of the file while it's being modified or deleted. Systems implement locking to prevent the classic ''interceding update'' scenario, which is a typical example of a race condition, by enforcing the serialization of update processes to any given file. The following example illustrates the interceding update problem: # Process A reads a customer record from a file containing account information, including the customer's account balance and phone number. # Process B now reads the same record from the same file, so it has its own copy. # Process A changes the account balance in its copy of the customer record and writes the record back to the file. # Process B, which still has the original ''stale'' value for the account balance in its copy of the customer record, updates the account balan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mkfs
In computer operating systems, mkfs is a command used to format a block storage device with a specific file system. The command is part of Unix and Unix-like operating systems. In Unix, a block storage device must be formatted with a file system before it can be mounted and accessed through the operating system's filesystem hierarchy. History The command was originally implemented in the first version of Unix as a method to initialize either a DECtape (using the "t" argument) or an RK03 disk pack (using the "r" argument). The initialization process would write formatting data to the device so that it contained an empty file system. It created the super-block, i-list, and free list on the storage device and established the root directory with entries for "." and ".." (self and parent, respectively). The RK03 disk packs had 4872 available blocks after initialization, while the tapes had 578 blocks (at 512 bytes/block). The mkfs executable was kept in the /etc directory instead of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesg
mesg is a Unix command that sets or reports the permission other users have to write to the current user's terminal using the talk and write commands. Usage It is invoked as: mesg n The 'y' and 'n' options respectively allow and disallow write access to the current user's terminal. When invoked with no option, the current permission is printed. Input redirection may be used to control the permission of another TTY. For example: % mesg is y % tty /dev/tty1 % mesg < /dev/tty2 is y % mesg n < /dev/tty2 % mesg < /dev/tty2 is n % mesg is y See also *List of Unix commands
This is a list of Unix commands as specified by IEEE Std 1003.1-2008, which is part of the Single UNIX Specification (SUS). These commands can be found on Unix operating systems and most Unix-like operatin ...
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Losetup
In Unix-like operating systems, a loop device, vnd (vnode disk), or lofi (loop file interface) is a pseudo-device that makes a computer file accessible as a block device. Before use, a loop device must be connected to an extant file in the file system. The association provides the user with an application programming interface (API) that allows the file to be used in place of a block special file (cf. device file system). Thus, if the file contains an entire file system, the file may then be mounted as if it were a disk device. Files of this kind are often used for CD ISO images and floppy disk images. Mounting a file containing a file system via such a loop mount makes the files within that file system accessible. They appear in the mount point directory. A loop device may allow some kind of data elaboration during this redirection. For example, the device may be the unencrypted version of an encrypted file. In such a case, the file associated with a loop device may be another pse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kill (Unix)
In computing, kill is a command that is used in several popular operating systems to send signals to running processes. Implementations Unix and Unix-like In Unix and Unix-like operating systems, kill is a command used to send a signal to a process. By default, the message sent is the termination signal, which requests that the process exit. But ''kill'' is something of a misnomer; the signal sent may have nothing to do with process killing. The kill command is a wrapper around the kill() system call, which sends signals to processes or process groups on the system, referenced by their numeric process IDs (PIDs) or process group IDs (PGIDs). kill is always provided as a standalone utility as defined by the POSIX standard. However, most shells have built-in kill commands that may slightly differ from it. There are many different signals that can be sent (see ''signal'' for a full list), although the signals in which users are generally most interested are SIGTERM ("termina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ipcs
ipcs is a Unix and Linux command to list System V InterProcess Communication System's API kernel entities to ''stdout''. System V IPC kernel entities are: *Shared memory segments *Message queues *Semaphore arrays Implementations On Linux, the command is provided by the util-linux package. The command has also been ported to the IBM i operating system. See also *List of Unix commands *ipcrm ipcrm is a Unix and Linux command which will mark System V interprocess communication API kernel entities for removal. Actual removal is deferred until the last connected process has detached. System V IPC kernel entities are: *Shared memory (int ... References External links * {{Unix commands Unix SUS2008 utilities IBM i Qshell commands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ipcrm
ipcrm is a Unix and Linux command which will mark System V interprocess communication API kernel entities for removal. Actual removal is deferred until the last connected process has detached. System V IPC kernel entities are: *Shared memory (interprocess communication) segments *Message queues *Semaphore arrays Implementations On Linux, the command is provided by the util-linux package. The command has also been ported to the IBM i operating system. See also *List of Unix commands *ipcs ipcs is a Unix and Linux command to list System V InterProcess Communication System's API kernel entities to ''stdout''. System V IPC kernel entities are: *Shared memory segments *Message queues *Semaphore arrays Implementations On Linux, the c ... – provide information on ipc facilities References External linksipcrm- ipcrm man page {{Unix commands Unix SUS2008 utilities IBM i Qshell commands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionice
nice is a program found on Unix and Unix-like operating systems such as Linux. It directly maps to a kernel call of the same name. nice is used to invoke a utility or shell script with a particular CPU priority, thus giving the process more or less CPU time than other processes. A niceness of -20 is the highest priority and 19 is the lowest priority. The default niceness for processes is inherited from its parent process and is usually 0. Etymology ''Niceness value'' is a number attached to processes in *nix systems, that is used along with other data (such as the amount of I/O done by each process) by the kernel process scheduler to calculate a process' 'true priority'which is used to decide how much CPU time is allocated to it. The program's name, nice, is an allusion to its task of modifying a process' niceness value. The term ''niceness'' itself originates from the idea that a process with a higher niceness value is ''nicer'' to other processes in the system and to users ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hex Dump
In computing, a hex dump is a hexadecimal view (on screen or paper) of computer data, from memory or from a computer file or storage device. Looking at a hex dump of data is usually done in the context of either debugging, reverse engineering or digital forensics. In a hex dump, each byte (8 bits) is represented as a two-digit hexadecimal number. Hex dumps are commonly organized into rows of 8 or 16 bytes, sometimes separated by whitespaces. Some hex dumps have the hexadecimal memory address at the beginning. Some common names for this program function are hexdump, hd, od, xxd and simply dump or even D. Samples A sample text file: 0123456789ABCDEF /* ********************************************** */ Table with TABs (09) 1 2 3 3.14 6.28 9.42 as displayed by Unix hexdump: 0000000 30 31 32 33 34 35 36 37 38 39 41 42 43 44 45 46 0000010 0a 2f 2a 20 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 0000020 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a * 0000040 2a 2a 20 2a 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Getopt
Getopt is a C library function used to parse command-line options of the Unix/POSIX style. It is a part of the POSIX specification, and is universal to Unix-like systems. It is also the name of a Unix program for parsing command line arguments in shell scripts. History A long-standing issue with command line programs was how to specify options; early programs used many ways of doing so, including single character options (-a), multiple options specified together (-abc is equivalent to -a -b -c), multicharacter options (-inum), options with arguments (-a arg, -inum 3, -a=arg), and different prefix characters (-a, +b, /c). The function was written to be a standard mechanism that all programs could use to parse command-line options so that there would be a common interface on which everyone could depend. As such, the original authors picked out of the variations support for single character options, multiple options specified together, and options with arguments (-a arg or -aar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
