lowercase The tt su tt command, also referred to as super user ref cite book title Unix Source Code url http www.bsdlover.cn study UnixTree V5 usr source s2 su.c.html ref substitute user , spoof user , set user or switch user , allows a computer operator to change the current user account associated with the running virtual console . By default, and without any other command line Parameter computer programming argument , this will Privilege escalation elevate the current user to the superuser of the local system. Usage When run from the command line, tt su tt asks for the target user s password, and if authenticated, grants the operator access to that account and the files and directories that account is permitted to access. source lang bash john localhost su Password root localhost home john exit logout john localhost source Additionally, one can switch to another user who is not the superuser e.g. tt su jane tt . source lang bash john localhost su jane Password jane localhost home john exit logout john localhost source It should generally be used with a hyphen by Superuser administrator s tt su tt , which is identical to tt su root tt , which can be used to start a login shell. This way users can assume the user environment of the target user source lang bash john localhost su jane ... Unix like systems have a Wheel Unix term wheel group of users, and only allow these users to su to root. ref name levi cite book title UNIX Administration A Comprehensive Sourcebook for Effective ... group ref See also Unix security List of Unix programs Comparison of privilege authorization features ... of su dictionary.die.net unix commands Category Unix user management and support related utilities Category System administration unix stub ar cs Su Unix de Su Unix es Su Unix fa Su fr Su Unix ko Su it Su Unix hu Su Unix nl Su Unix ja Su Unix pl Su Unix pt Su Unix ro Su Unix ru Su sr Su vi Su Unix ... more details
, then the shell procedure exits. The special shell variable represents the number of positional parameters entered on the command line that starts this shell procedure. See also List of Unix utilities Bourne shell Korn shell KornShell KornShell is the proper name as written by its author Z Shell GNU tt Bash Unixshell bash tt C shell tt tcsh tt The tt find tt program. References nowiki See http ...Cleanup rewrite date May 2009 lowercase title test Unix test is a command in Unix that evaluates conditional expressions. Syntax test expression or expression Description The test command evaluates the expression parameter. In some shells such as FreeBSD sh 1 , it is actually a shell builtin, even though external version still exists. In the second form of the command, the brackets must be surrounded by blank spaces. You must test explicitly for file names in the C shell. File name substitution globbing causes the shell script to exit. Functions and operators are treated as separate parameters by the test command. The expression parameter refers to a statement that is checked for a true or false condition. Functions The following functions are used to construct this parameter e FileName FileName exists. Note All remaining functions return true if the object file or string exists, and the condition ... Group identifier Unix Group ID bit is set. h FileName FileName is a symbolic link . k FileName FileName ... terminal terminal . u FileName FileName s Set User identifier Unix User ID bit is set. w FileName FileName ..., documentation for test ref and are therefore not portable. In portable shell scripts, the same ... specified by the first positional parameter to the shell procedure, 1, does not exist or is of size ... test argument expected. 2. To do a complex comparison, type if lt 2 o e 1 then exit fi If the shell ... and ref tags, and the template below. nowiki references Unix commands Category Unix SUS2008 utilities Category Conditional constructs fr Test Unix hu Test Unix pl Test Unix ru Test uk Test ... more details
refimprove date December 2011 No footnotes date February 2008 lowercase title cat Unix The cat program is a standard Unix utility that Concatenation concatenates and lists files. The name is an abbreviation of wikt catenate catenate , a synonym of concatenate. Specification The Single Unix Specification ... tt Unix culture Jargon File definition The Jargon File version 4.4.7 lists this as the definition ... of browsing it carefully. Usage considered silly. Rare outside Unix sites. See also tt dd Unix dd tt , Block transfer instruction BLT . Among Unix fans, tt cat 1 tt is considered an excellent example ... of lines of text, but works with any sort of data. Among Unix critics, tt cat 1 tt is considered the canonical ... of a file to standard output. A UUOC campaign will eliminate the inefficiency from shell scripts ... era unix award.html ref In British English British Hacker culture hackerdom the activity of fixing ... file1.txt and file2.txt in binary mode to one file, file3.txt. See also List of Unix utilities code Split Unix split code , a command that splits a file into pieces which cat can then rejoin. zcat ... Mrsi paste Unix References Reflist External links man cu cat SUS concatenate and print files http harmful.cat v.org cat v UNIX Style, or cat v Considered Harmful A paper by Rob Pike on proper Unix command design using cat as an example. Manual pages http man.cat v.org unix 1st 1 cat cat 1 original manual page in the First Edition of Unix . man format 1 cat http www.gnu.org software coreutils ... 1 cat catenate files Plan 9 from Bell Labs manual Other http www.iki.fi era unix award.html Useless Use Of Cat Award Unix commands Category Unix text processing utilities Category Standard Unix programs Cat Category Unix SUS2008 utilities ar ca Cat Unix cs Cat de Cat Unix el Cat Unix es Cat Unix fa Cat fr Cat Unix ko Cat it Cat Unix hu Cat Unix ms Cat UNIX ro Cat Unix nl Cat Unix ja Cat UNIX pl Cat Unix pt Cat Unix ru Cat sl Cat Unix sv Cat tr Cat Unix uk Cat zh Cat Unix ... more details
DISPLAYTITLE code toor code Unix Toor , the word root spelled backwards, is an alternative superuser account in Unix like operating systems, particularly BSD and variants. Purpose In Unix, it is traditional to keep the root File system filesystem as small as reasonably possible, moving larger programs and rapidly changing data to other, optional parts of the system. This increases the likelihood that the system can be brought to a semi usable state in the case of a partial system failure. It also means that the superuser account, necessary for repairing a broken system, should not depend on any programs outside of this small core. To this end, the root account is often configured with a Shell computing shell which is small, efficient, and dependable, but awkward for daily use. The toor account is intended as a solution to this problem. It is identical to root, but is configured to use a different, more featureful shell. Alternately, toor may be configured with the emergency shell, allowing root the freedom to use the featureful one. Implementation In a Unix like system, each user has a User identifier Unix user ID number, which is what the Kernel computer science kernel uses to distinguish users and to manage user File system permissions permissions . User ID 0 is reserved as the superuser account, and is given permission to do anything on the system. Users log in by username, not by ID number, and a user s choice of login shell is also managed by name. This separation between name and number allows a given user ID to be associated with more than one username, each having its own shell. Security considerations The presence of a toor account or the presence of more than one account with a user ID of 0 triggers a warning in many security auditing systems. This is valuable, since if the system administrator did not intend for a second superuser account, then it may mean that the system ... Unix de Root Account ... more details
date start date and age YYYY MM DD frequently updated programming language operating system Unix platform size language status genre license Unixshell website The Thompson shell was the first Unixshell , introduced in the first version of Unix in 1971, and was written by Ken Thompson computer ... line interface and led to the development of the later Unix shells. History The name shell for a command line interpreter and the concept of making the shell a user program outside of the operating system Kernel computer science kernel were introduced in Unix s precursor Multics . An early feature of the Thompson shell was a compact syntax for input output redirection. In Multics, redirecting the input or output of a command required separate commands to start and stop redirection in Unix ... s Workbench UNIX distribution, most notably John Mashey , began modifying the Thompson shell ... shell was replaced as the main Unixshell by the Bourne shell in Unix Version 7 and the C ... all modern Unix and Unix like systems are descended from V7 and 2BSD, the Thompson shell is generally ... 1st 1 sh Manual page for the Thompson shell in Unix 1st Edition . http cm.bell labs.com cm cs who dmr hist.html The Evolution of the Unix Time Sharing System describes the early development of the shell ...Infobox software name Thompson shell logo File screenshot File caption collapsible author Ken Thompson ... for input or the > symbol for output, and the shell would redirect I O for the duration of the command. This syntax was already present by the release of the first version of Unix in 1971. A later addition was the concept of pipeline Unix pipes . At the suggestion of Douglas McIlroy , the redirection ... exactly the same result as command1 command2 The Thompson shell syntax for redirection with < and > , and piping with , has proven durable and has been adopted by most other Unix shells and command ... and replacements The shell s design was intentionally minimalistic even the if and goto statements ... more details
lowercase title touch Unix touch is a standard Unix computer program program used to change a computer file file s access and modification system time timestamps . It is also used to create a new empty file. History A touch utility appeared in Version 7 AT&T UNIX. The version of tt touch tt bundled in GNU coreutils was written by Paul Rubin , Arnold Robbins , Jim Kingdon , David MacKenzie programmer David MacKenzie Specification The Single Unix Specification SUS specifies that tt touch tt should change the access times, modification times, or both, for a file. The file is identified by a pathname supplied as a single argument. It also specifies that if the file identified does not exist, the file is created and the access and modification times are set as specified. If no new timestamps are specified, tt touch tt uses the current time. Usage The SUS mandates the following options tt a tt , change the access time only tt c tt , if the file does not exist, do not create it and do not report this condition tt m tt , change the modification time only tt r file tt , use the access and modification times of tt file tt tt t time tt , use the time specified in the format below to update the access ... Unix and Unix like operating systems may add extra options. For example, GNU tt touch tt adds a tt ... touch source Other operating systems Programs that perform similar operations as the Unix code touch ... metouch Synesis Software File Touch Shell Extension freeware for Windows br http www.flos freeware.ch archive.html The ntouch dtouch page See also System time List of Unix programs External links ... Unix Specification http www.bellevuelinux.org touch.html examples showing how to use touch Dead link ... page from OpenBSD unix commands Category Standard Unix programs Category Unix SUS2008 utilities cs Touch Unix de Touch Unix es Touch Unix fa Touch fr Touch Unix ko Touch it Touch Unix ka Touch hu Touch Unix ja Touch UNIX pl Touch Unix pt Touch inform tica ro Touch Unix ... more details
lowercase title history Distinguish Unix History The various Unix shells maintain a record of the commands issued by the user during the current session. The history command manipulates this history list. In its simplest form, it prints the history list. Options allow for the recall and editing of particular commands and for setting parameters such as the number of past commands to retain in the list. In early versions of Unix the history command was a separate program. However, most shells have long included the history command as a shell built in, so the separate program is no longer in common use. Since most current history commands are shell built ins, details depend on the choice of shell. tcsh history hTr n history S L M filename history c The first form prints the history event list. If n is given only the n most recent events are printed or saved. With h , the history list is printed without leading numbers. If T is specified, timestamps are printed also in comment form. This can be used to produce files suitable for loading with history L or source h . With r, the order of printing is most recent first rather than oldest first. With S , the second form saves the history list to filename. If the first word of the savehist shell variable is set to a number, at most that many lines are saved. If the second word of savehist is set to merge , the history list is merged with the existing history file instead of replacing it if there is one and sorted by time stamp. Merging is intended for an environment like the X Window System with several shells in simultaneous use. Currently it succeeds only when the shells quit nicely one after another. With L , the shell appends filename, which is presumably a history list saved by the S option or the savehist mechanism, to the history ... form of the history list. The last form clears the history list. unix commands Category Unix software ru History UNIX ... more details
compromise. Users who prefer the more logical 1024 byte quantity can easily tt Alias Unixshell ...no footnotes date December 2011 lowercase code df code abbreviation for d isk f ree is a standard Unix computer program used to display the amount of available disk space for filesystems on which the invoking user has appropriate read access. tt df tt is usually implemented by reading the mtab file or using statfs . tt df tt first appeared in Version 1 AT&T UNIX . Usage The Single UNIX Specification specifications for tt df tt are source lang bash df k P t del file... source tt k tt Use 1024 byte units, instead of the default 512 byte units, when writing space figures. tt P tt Use a standard, portable, output format tt t tt If X Open System Interfaces Extension XSI compliant, show allocated space as well Dubious date May 2010 tt h tt Display in Kb, Mb, or Gb tt file tt Write the amount of free space of the file system containing the specified file Most Unix and Unix like operating systems add extra options. The BSD and GNU coreutils versions include tt h tt , where free space is listed in human readable format, adding units with the appropriate SI prefix e.g. 10MB , tt i tt , listing inode usage, and tt l tt , restricting display to only local filesystems. GNU tt df tt includes tt T tt as well, listing filesystem type information, but the GNU tt df tt shows the sizes in 1K blocks by default. Specification The Single Unix Specification SUS specifies by default space is reported in blocks of 512 bytes, and that at a minimum, the file system names and the amount of free space. The use ... dev hd10opt 65536 26004 61 654 4 opt source See also List of Unix programs External links man cu df ... df.html The df Command by The Linux Information Project LINFO unix commands Category Standard Unix programs Category Unix SUS2008 utilities cs Df Unix de Df Unix fr Df Unix it Df Unix ka Df hu Df Unix pl Df Unix pt Df Unix ro Df Unix ru Df uk Df es Df unix ... more details
essay like date March 2012 lowercase rm short for remove is a basic UNIX command used to remove objects such as files, directories, device node s, symbolic link s, and so on from the filesystem. To be more precise, rm removes references to objects from the filesystem, where those objects might have had multiple references for example, a file with two different names , and the objects themselves are discarded only when all references have been removed and no programs still have open handles to the objects. This allows for scenarios where a program can open a file, immediately remove it from the filesystem ... Unix shred are available which specifically provide data wiping capability. Example To remove a file ... lang bash rm i foo remove foo? y source Context rm is generally only seen on UNIX derived operating ... the recycle bin computing recycle bin ., ref http www.faqs.org faqs unix faq faq part3 section 6.html ... files from a directory if the directory is write protected. rm is often overlain by a C shell Aliasing alias or Bourne shell function of rm i so as to avoid accidental deletion of files. If a user ... tt , and others is frequently used in jokes and anecdotes about Unix disasters ref name Linux UNIX Delete a file cite web last Gite first Vivek title Linux UNIX Delete a file url http www.cyberciti.biz faq howto linux unix delete remove file publisher Nixcraft accessdate 24 November 2011 ref . The tt ... source It s important to note that this function should not be made into a shell script, which would ... See also srm Unix secure remove file in Unix unlink Unix unlink the underlying system call called by this user ... links wikibooks Guide to Unix Commands File System Utilities rm rm man cu rm SUS remove directory entries Unix commands Category Unix SUS2008 utilities Category File deletion ar bg Rm ca Rm cs Rm Unix de Rm Unix es Rm fa Rm fr Rm Unix ko Rm it Rm Unix ka Rm hu Rm Unix nl Rm Unix ja Rm UNIX pl Rm Unix pt Rm ro Rm Unix ru Rm fi Rm Unix uk Rm ... more details
is implemented by an anonymous pipe . Filter Unix Filter program s are often used in this configuration. The concept was invented by Douglas McIlroy for Unixshell s and it was named by analogy ... of the authors of the early Unixshell command shells , after he noticed that much of the time they were ... pipeline handling. Category Inter process communication Category Unix cs Roura Unix fr Tube shell ...Image Pipeline.svg thumb 280px A pipeline of three programs run on a text terminal In Unix like computer ... Unix pipeline can be thought of as left associative Infix notation infix operation whose operands are programs ... as their input or output . Pipelines in command line interfaces All widely used Unix and Windows ..., is often called pipe character . The shell starts the processes and arranges for the necessary ... . Shouldn t this be in the shell article? As with all shell commands, a command line can be extended ... additional syntax for changing this behaviour. In the C shell csh shell, for instance, using & instead ... to the next process. The Bourne Shell can also merge standard error, using tt 2 &1 tt , as well as redirect it to a different file. Pipemill In the most commonly used simple pipelines the shell connects ... the shell itself is doing no direct processing of the data flowing through the pipeline. However, it s possible for the shell to perform processing directly. This construct generally looks something ... hosts from the while loop. ref http 72.14.189.113 howto shell while ssh ref To prevent this, redirect stdin from dev null. dev null In the case of ssh, you may also use n to prevent Secure Shell ssh .... The Unix code pipe code system call asks the operating system to construct a new anonymous pipe ... no ability to seek. To avoid deadlock and exploit parallelism, the Unix process with one ... tee command tee code . Implementation In most Unix like systems, all processes of a pipeline ... Unix pipes apart from other pipe implementations, is the concept of Buffer computer science buffering ... more details
lowercase The Unix banner Computer program program outputs a large ASCII art version of the text that is supplied to it as its command line argument program argument s. One use of the command is to create highly visible separator pages for print job s. ref name PracticalUnix cite book title Practical UNIX author Steve Moritsugu, Sanjiv Guha, James Edwards, David Pitts pages 220&ndash 221 publisher Que Publishing date 2000 isbn 078972250X isbn13 9780789722508 ref Operation Each argument is truncated at 10 characters and printed on a line of its own. To print multiple words on a single line, they must therefore be passed as a single argument, which is done from the shell computing shell by escaping or quoting the words as appropriate. ref name PracticalUnix A related, and more flexible, program is FIGlet , which can display text in different fonts and orientations. ref cite book title UNIX in a Nutshell author Arnold Robbins pages 24 publisher O Reilly date 2006 isbn 0596100299 isbn13 9780596100292 ref Implementation The way that the program is implemented internally is error prone and antiquated. The character fonts used are hardwired into the program code itself, as statically initialized data structures. Two data structures are used. The first is a data table comprising a sequence of printing instructions that encode the bitmap for each character in an encoding specific to the code banner code program . The second is an index into that table that indicates, for each character .... ref name Spinellis Versions A partial list of versions By AT&T , in UNIX System V . ref http www.zen77087.zen.co.uk ... references Further reading cite book title UNIX Unbounded author Amir Afzal chapter The banner command pages 462&ndash 463 publisher Prentice Hall date 2008 isbn 0131194496 isbn13 9780131194496 unix commands Category Unix text processing utilities fr Banner Unix hu Banner Unix ja Banner UNIX pl Banner Unix ru Banner ... more details
is tab . Space and other characters with special meanings within the context of the Unixshellshell in use must be enquoted or escaped as necessary. s Bypasses lines which contain no field delimiters ...lowercase In computing , cut is a Unix command line utility which is used to extract sections from each line of input usually from a computer file file . It is currently part of the GNU Core Utilities GNU coreutils package and the BSD Base System. It first appeared in UNIX System III AT&T System III UNIX in 1982. ref http www.unix.com man page FreeBSD 1 CUT ref Extraction of line segments can typically be done by byte s code b code , character computing character s code c code , or fields code f code separated by a delimiter code d code &mdash the tab character by default . A range must be provided in each case which consists of one of code N code , code N M, code code N code code N code to the end of the line , or code M code beginning of the line to code M code , where N and M are counted from 1 there is no zeroth value . Since version 6, an error is thrown if you include a zeroth value. Prior to this the value was ignored and assumed to be 1. Examples Assuming a file named file containing the lines foo bar baz qux quux one two three four five six seven alpha beta gamma delta epsilon zeta eta teta iota kappa lambda mu the quick brown fox jumps over the lazy dog To output the fourth through tenth characters of each line cut c 4 10 file This gives the output bar ba two th ha beta ... to process as input. If no file is specified then standard input will be used. See also List of Unix programs grep paste Unix paste awk References reflist External links http www.softpanorama.org ... from each line of files . unix commands Category Unix text processing utilities Category Standard Unix programs Category Unix SUS2008 utilities cs Cut de Cut Unix eo Cut fr Cut Unix ko Cut it Cut Unix ja Cut no Cut pl Cut Unix ro Cut Unix ru Cut sv Lista ver golftermer Cut uk Cut zh Cut Unix ... more details
Refimprove date August 2011 Spell is the standard English language spell checker for Unix . Spell was originally written by Stephen C. Johnson of Bell Labs in 1975. Douglas McIlroy later improved its accuracy, performance, and memory use, and described his work and spell in general in his 1982 paper http cm.bell labs.com cm cs who doug spell.ps.gz Development of a Spelling list . Spell has a simple command line interface It goes over all the words in a given text file, and prints a sorted list of unique misspelled words in that file. It does not provide any interface for looking for those words in the file, or helping to correct the mistakes. In 1983, a different spell checker, ispell the interactive spell checker was ported to Unix. ispell had a user interface for showing the spelling mistakes in context, and suggest how to correct them. Since then, the original Spell tool has been mostly considered obsolete. Another reason why Spell is considered obsolete is that it only supports the English language. Modern spell checkers for Unix and Linux systems, such as aspell , MySpell and hunspell all support a multitude of different languages and character sets. The Single Unix Specification has officially declared Spell a legacy application , stating that this was done because there is no known technology that can be used to make it recognise general language for user specified input without providing a complete dictionary along with the input file. ref http pubs.opengroup.org onlinepubs 007908799 xcu spell.html ref Nevertheless, the Single Unix Specification does not standardize any other spell checking utility to take Spell s place. Because of Spell s problems and the superiority ... simpler shell script For example, the spell command in Fedora Linux simply runs aspell, as cat aspell ... p unix spell Original unix spell source code References reflist Unix commands Category 1975 software Category Standard Unix programs ... more details
code is a hard or symbolic link to code bin bash code , the Bash Unixshell Bourne Again shell . Using Bash Unixshell syntax specific to Bash while maintaining a shebang pointing to the Bourne shell is not portable. ref http www.pixelbeat.org programming shell script mistakes.html pixelbeat.org Common shell script mistakes It s much better to test scripts directly in a POSIX compliant shell if possible ... for shell scripts, is apparent in the documentation from Version 7 Unix in 1979, ref http ... line of a Script computing script . Under Unix like operating systems, when a script with a shebang ... usually this is the Bourne shell or a compatible shell , passing tt path to script tt as the first ... Some typical shebang lines code bin sh code Execute the file using sh, the Bourne shell , or a compatible shell code bin csh code Execute the file using csh, the C shell , or a compatible shell ... on the command line. Consider a Bourne shell script that is identified by the path ... the Bourne shell , then the end result is that all of the shell commands in the file tt some path to foo ... shell language and in the languages understood by many other interpreters , the entire shebang ... that code sh code is a shell capable of a syntax similar to the Bourne shell , although it does not require ... compatible shell at code usr xpg4 bin sh code . ref cite web url http pubs.opengroup.org onlinepubs ... 8 the standard character encoding for text files on many Unix like systems is ASCII compatible, assigning ... Unix like systems. ref cite web title FAQ UTF 8, UTF 16, UTF 32 & BOM Can a UTF 8 data stream contain ... web url http www.cl.cam.ac.uk mgk25 unicode.html ucsutf title UTF 8 and Unicode FAQ for Unix Linux ... be recognised as such by a simple algorithm. There have been rumors that some old versions of UNIX look ... In ulm.de date accessdate 2010 06 16 ref On Unix like operating systems, new image files are started ..., scripts can be marked with the setuid attribute, set user ID, a Unix feature which means that a program ... more details
lowercase title patch Unix File patching.png thumb A screenshot of using patch. patch is a Unix computer program program that updates text files according to instructions contained in a separate file, called a patch file . The patch file also called a patch for short is a text file that consists of a list of differences and is produced by running the related diff program with the original and updated file as arguments. Updating files with patch is often referred to as applying the patch or simply patching the files. History The original patch program was written by Larry Wall who went on to create the Perl programming language and posted to tt mod.sources tt ref cite news url http groups beta.google.com group mod.sources browse thread thread c5240ceb77b7f586 488b0929254d936a group mod.sources title patch version 1.3 author Larry Wall date May 24, 1985 ref which later became tt comp.sources.unix tt in May 1985. A newer version of the program is part of the GNU project and is maintained by the Free Software Foundation FSF . Usage context Developed by a programmer for other programmers, patch was frequently used for updating of source code to a newer version. Because of this, many people came to associate patches with source code, whereas patches can in fact be applied to any text. Patched ... command in a shell diff u oldFile newFile mods.diff u tells diff to output unified diff format To apply a patch, one could run the following command in a shell patch mods.diff This tells patch ... of patch Originally written for Unix and Unix like systems, patch has also been ported to Microsoft ... . See also Patch computing Quilt software quilt rsync List of Unix programs IBM mainframe utility ... show statistics from output of diff Category 1985 software Category Unix SUS2008 utilities Category Patch utilities ar cs Patch da Patch program de Patch Unix el Patch Unix es Patch Unix ja Patch no Patch program pt Patch Unix ru Patch UNIX tr Patch Unix zh Patch ... more details
lowercase fg is a job control Unix job control command in Unix and Unix like operating systems that resumes execution of a suspended Process computing process by bringing it to the foreground and thus redirecting its standard input and standard output output streams to the user s computer terminal terminal . ref name man http www.computerhope.com unix ufg.htm fg man page ref fg is required to be included in an operating system in order for it to be POSIX compliant. ref name POSIX commands http manuals.fujitsu siemens.com servers bs2 man man us posix v6 0 posix k.pdf POSIX BS2000 OSD Commands User Guide ref See also bg Unix bg , the complementary command that sends a process to the background SIGCONT References Reflist External links man cu fg SUS run jobs in the foreground Unix commands Category Standard Unix programs Category Unix SUS2008 utilities Unix stub ca Fg Unix el Fg Unix fr Fg Unix pl Fg Unix zh Fg Unix ... more details
lowercase title printf Refimprove date July 2010 printf print f ormatted shell builtin command and utility program accepts a format string , which specifies methods for formatting items and a list of items to be formatted. Named for the intention of printing to a printer, it actually outputs to STDOUT . Characters in the format string are copied to the output or, if a is encountered, are used to format an item. In addition to the standard formats, b causes printf to expand backslash escape sequences for example n for newline and q outputs an item that can be used as shell input. The format string is reused if there are more items then format specs . Unused format specs are provide a zero value or null string. See printf function for more details. Example for NUMBER in 4 6 8 9 10 do printf 03d d n NUMBER RANDOM done 004 26305 006 6687 008 20170 009 28322 010 4400 example output of usage from bash builtin printf usage printf v var format arguments example output of usage from printf utility usage printf format arguments ... Printf References man page for shell or printf utility Category Standard Unix programs ... more details
lowercase Image Pg Unix screenshot.png thumbnail Example output of the tt pg tt command in xterm . pg is a terminal pager program on Unix and Unix like systems for viewing text file s. It can also be used to page through the output of a command via a pipe Unix pipe . pg uses an interface similar to vi , but commands are different. ref http www.computerhope.com unix upg.htm Linux Unix pg command ref more command more , and less Unix less are more commonly used paging programs. See also less Unix less more command more References reflist Unix commands unix stub Category Terminal pagers ... more details
lowercase In computer software , tt id tt is a program in Unix like operating system s that prints the User identifier Unix user or Group identifier Unix group identifier of the account by which the program is executed an example of the command tt id tt as executed by user tt alice tt source lang bash alice darkstar id uid 1016 alice gid 100 users groups 100 users source The superuser root account has a UID of 0 source lang bash root darkstar id uid 0 root gid 0 root groups 0 root source The tt whoami tt utility has been obsoleted by the tt id tt utility and displays a user s ID as a name source lang bash alice darkstar whoami alice alice darkstar id un Where u refers to user and n refers to name alice source See also List of Unix programs User identifier Unix UID Group identifier Unix GID tt Who Unix who tt tt uname tt References man cu id SUS return user identity Unix commands Category Unix user management and support related utilities Category Unix SUS2008 utilities cs Id Unix el Id Unix fr Id Unix hu Id Unix ja Id UNIX pl Id Unix pt Id Unix ru Id uk Id ... more details
lowercase Unreferenced date March 2007 The tt install tt command is a standard Unix program used to copy Computer file files and set file permissions . Category Standard Unix programs Unix stub ... more details
lowercase bg is a job control Unix job control command in Unix and Unix like operating systems that resumes execution of a suspended Process computing process without bringing it to the foreground ref name bg man page http pwet.fr man linux commandes posix bg bg man page ref the resumed process continues to execute in the background without receiving user input from the Computer terminal terminal . bg is required to be included in an operating system in order for it to be POSIX compliant. ref name POSIX commands http manuals.fujitsu siemens.com servers bs2 man man us posix v6 0 posix k.pdf POSIX BS2000 OSD Commands User Guide ref See also fg Unix fg , the complementary command that brings a process to the foreground References Reflist Unix commands Category Standard Unix programs Category Unix SUS2008 utilities unix stub ca Bg Unix el Bg Unix fr Bg Unix zh Bg Unix ... more details
Unreferenced auto yes date December 2009 Lowercase The command w on many Unix like operating system s provides a quick summary of every user logged into a computer, what that user is currently doing, and what Load computing load all the activity is imposing on the computer itself. The command is a one command combination of several other Unix programs tt Who Unix who tt , tt uptime tt , and tt Ps Unix ps a tt . Sample output this may vary between systems source lang text w 11 12am up 608 day s , 19 56, 6 users, load average 0.36, 0.36, 0.37 User tty login idle what smithj pts 5 8 52am w jonesm pts 23 20Apr06 28 bash harry pts 18 9 01am 9 pine peterb pts 19 21Apr06 emacs nw html index.html janetmcq pts 8 10 12am 3days csh singh pts 12 16Apr06 5 29 usr bin perl w perl test program.pl source External links man 1 w Unix commands Category Unix user management and support related utilities Unix stub cs W Unix el W Unix es W Unix ko W hu W Unix ja W UNIX pl W Unix pt W Unix ru W UNIX zh W Unix ... more details
saved book title Unix subtitle cover image Poundexclam.svg cover color Black Unix Introduction UnixUnix wars Historically significant corporations AT&T Bell Labs Hewlett Packard IBM Novell SCO Group Sun Microsystems Unix standards and organizations The Open Group X Open POSIX Single UNIX Specification Unix operating systems Berkeley Software Distribution 1977 Berkeley Software Distribution Version 7 Unix 1979 Version 7 Unix SunOS 1982 SunOS UNIX System V 1983 UNIX System V HP UX 1984 HP UX IBM AIX 1986 AIX IRIX 1988 IRIX SCO OpenServer 1989 SCO OpenServer Solaris operating system 1992 Solaris Tru64 UNIX 1992 Tru64 UNIX UnixWare 1992 UnixWare OS X 2001 Mac OS X Unix like operating environments Unix like Cygwin DragonFly BSD FreeBSD GNU Interix Linux NetBSD NeXTSTEP OpenBSD OpenSolaris Plan 9 from Bell Labs Legal battles and controversies SCO Linux controversies SCO v. IBM SCO v. Novell SCO and SGI Red Hat v. SCO USL v. BSDi Category Wikipedia books on computing ... more details
A port of Version 6 Unix to the Interdata 7 32 was completed by Richard Miller and Ross Nealon at Wollongong University , Australia , during 1976 1977. This project was supervised by professor Juris Reinfelds . The resulting system was called Wollongong Interdata UNIX, Level 6 . This distribution also included utilities developed at Wollongong, and later releases had features of V7, notably its C programming language C compiler . Wollongong Unix was the first ever port to a platform other than the PDP series of computers, proving that portable operating systems were indeed feasible, and that C was the language in which to write them. In 1980, this version was licensed to The Wollongong Group in Palo Alto that published it as Edition 7. See also Version 7 Unix Ancient UNIX External links http minnie.tuhs.org UnixTree V6 V6 source code http minnie.tuhs.org UnixTree Interdata v6 Wollongong Interdata UNIX source code http www.graphviz.org Gallery directed unix.svg a family tree of Unix, which includes Wollongong UnixUnix like Category Unix variants Category Discontinued operating systems Unix stub ... more details
. su Unix su , sudo , Secure Shell ssh only, no remote root logins Software Maintenance Patching ...Howto date August 2011 Unix security refers to the means of Computer security securing a Unix or Unix ... practices. Wikibooks UNIX Computing Security Design concepts Permissions A core security feature in these systems is the File system permissions permissions system. All files in a typical Unix style ... 745720 Sep 8 2002 bin sh Unix permissions permit different users access to a file. Different user groups have different permissions on a file. More advanced Unix filesystems include the Access Control ... Users under Unix style operating systems often belong to managed groups with specific access permissions. This enables users to be grouped by the level of access they have to this system. Many Unix ... Unix term wheel Group identifier Unix user privileges group in order to access the tt su tt command. ref name levi cite book title UNIX Administration A Comprehensive Sourcebook for Effective Systems ... 1351 1 ref Issues Most Unix and Unix like systems have an account or group which enables a user ... techniques Unix has many tools that can improve security if used properly by users and administrators ... important things a user can do to improve Unix security. In Unix systems, the essential information ... shell bin An example would be xfze 1 zuW2nX3sslp3qJm9MYDdglEApAc36r 1000 100 Jos Carlos D. S. Saraiva ... when the account becomes unusable The date expressed as the number of days since Unix epoch January 1st, 1970 when the account is expired These fields may be used to improve Unix security by enforcing ... Foreign Address state tcp6 0 0 localhost.smtp . LISTEN tcp6 0 0 .ssh . LISTEN Active UNIX domain ... that on this machine only the Secure shell SSH service is listening to the public network interface ... to a service may be further restricted by using a Unix security Firewalls firewall . File Systems File system security main File system permissions File system security within UNIX and Unix like ... more details
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