cat[选项][文件]

Aion.otn$cat--helpUsage:cat[OPTION]...[FILE]...ConcatenateFILE(s),orstandardinput,tostandardoutput.-A,--show-allequivalentto-vET-b,--number-nonblanknumbernonemptyoutputlines,overrides-n-eequivalentto-vE-E,--show-endsdisplay$atendofeachline-n,--numbernumberalloutputlines-s,--squeeze-blanksuppressrepeatedemptyoutputlines-tequivalentto-vT-T,--show-tabsdisplayTABcharactersas^I-u(ignored)-v,--show-nonprintinguse^andM-notation,exceptforLFDandTAB--helpdisplaythishelpandexit--versionoutputversioninformationandexitWithnoFILE,orwhenFILEis-,readstandardinput.Examples:catf-gOutputf's contents, then standard input, then g'scontents.catCopystandardinputtostandardoutput.GNUcoreutilsonlinehelp:<http://www.gnu.org/software/coreutils/>Forcompletedocumentation,run:infocoreutils'cat invocation'

Aion.Liu$cat--helpcat:illegaloption---usage:cat[-belnstuv][file...]

foriin$(seq110);doecho$i>>test.txt;done

cat/dev/null>test.txt

more[文件]

Aion.Liu$more--helpSUMMARYOFLESSCOMMANDSCommandsmarkedwith*maybeprecededbyanumber,N.NotesinparenthesesindicatethebehaviorifNisgiven.AkeyprecededbyacaretindicatestheCtrlkey;thus^Kisctrl-K.hHDisplaythishelp.q:qQ:QZZExit.---------------------------------------------------------------------------MOVINGe^Ej^NCR*Forwardoneline(orNlines).y^Yk^K^P*Backwardoneline(orNlines).f^F^VSPACE*Forwardonewindow(orNlines).b^BESC-v*Backwardonewindow(orNlines).z*Forwardonewindow(andsetwindowtoN).w*Backwardonewindow(andsetwindowtoN).ESC-SPACE*Forwardonewindow,butdon't stop at end-of-file.d^D*Forwardonehalf-window(andsethalf-windowtoN).u^U*Backwardonehalf-window(andsethalf-windowtoN).ESC-)RightArrow*Rightonehalfscreenwidth(orNpositions).ESC-(LeftArrow*Leftonehalfscreenwidth(orNpositions).ESC-}^RightArrowRighttolastcolumndisplayed.ESC-{^LeftArrowLefttofirstcolumn.FForwardforever;like"tail -f".ESC-FLikeFbutstopwhensearchpatternisfound.r^R^LRepaintscreen.RRepaintscreen,discardingbufferedinput.---------------------------------------------------Default"window"isthescreenheight.Default"half-window"ishalfofthescreenheight.---------------------------------------------------------------------------SEARCHING/pattern*Searchforwardfor(N-th)matchingline.?pattern*Searchbackwardfor(N-th)matchingline.n*Repeatprevioussearch(forN-thoccurrence).N*Repeatprevioussearchinreversedirection.ESC-n*Repeatprevioussearch,spanningfiles.ESC-N*Repeatprevioussearch,reversedir.&spanningfiles.ESC-uUndo(toggle)searchhighlighting.ESC-UClearsearchhighlighting.&pattern*Displayonlymatchinglines.---------------------------------------------------Asearchpatternmaybeginwithoneormoreof:^Nor!SearchforNON-matchinglines.^Eor*Searchmultiplefiles(passthruENDOFFILE).^For@StartsearchatFIRSTfile(for/)orlastfile(for?).^KHighlightmatches,butdon't move (KEEP position).^RDon't use REGULAR EXPRESSIONS.^WWRAPsearchifnomatchfound.---------------------------------------------------------------------------JUMPINGg<ESC-<*Gotofirstlineinfile(orlineN).G>ESC->*Gotolastlineinfile(orlineN).p%*Gotobeginningoffile(orNpercentintofile).t*Gotothe(N-th)nexttag.T*Gotothe(N-th)previoustag.{([*Findclosebracket})].})]*Findopenbracket{([.ESC-^F<c1><c2>*Findclosebracket<c2>.ESC-^B<c1><c2>*Findopenbracket<c1>.---------------------------------------------------Each"find close bracket"commandgoesforwardtotheclosebracketmatchingthe(N-th)openbracketinthetopline.Each"find open bracket"commandgoesbackwardtotheopenbracketmatchingthe(N-th)closebracketinthebottomline.m<letter>Markthecurrenttoplinewith<letter>.M<letter>Markthecurrentbottomlinewith<letter>.'<letter>            Go to a previously marked position.''Gotothepreviousposition.^X^XSameas'.ESC-M<letter>Clearamark.---------------------------------------------------Amarkisanyupper-caseorlower-caseletter.Certainmarksarepredefined:^meansbeginningofthefile$meansendofthefile---------------------------------------------------------------------------CHANGINGFILES:e[file]Examineanewfile.^X^VSameas:e.:n*Examinethe(N-th)nextfilefromthecommandline.:p*Examinethe(N-th)previousfilefromthecommandline.:x*Examinethefirst(orN-th)filefromthecommandline.:dDeletethecurrentfilefromthecommandlinelist.=^G:fPrintcurrentfilename.---------------------------------------------------------------------------MISCELLANEOUSCOMMANDS-<flag>Toggleacommandlineoption[seeOPTIONSbelow].--<name>Toggleacommandlineoption,byname._<flag>Displaythesettingofacommandlineoption.__<name>Displaythesettingofanoption,byname.+cmdExecutethelesscmdeachtimeanewfileisexamined.!commandExecutetheshellcommandwith$SHELL.|XcommandPipefilebetweencurrentpos&markXtoshellcommand.sfileSaveinputtoafile.vEditthecurrentfilewith$VISUALor$EDITOR.VPrintversionnumberof"less".---------------------------------------------------------------------------OPTIONSMostoptionsmaybechangedeitheronthecommandline,orfromwithinlessbyusingthe-or--command.Optionsmaybegiveninoneoftwoforms:eitherasinglecharacterprecededbya-,oranameprecededby--.-?........--helpDisplayhelp(fromcommandline).-a........--search-skip-screenSearchskipscurrentscreen.-A........--SEARCH-SKIP-SCREENSearchstartsjustaftertargetline.-b[N]....--buffers=[N]Numberofbuffers.-B........--auto-buffersDon't automatically allocate buffers for pipes.-c........--clear-screenRepaintbyclearingratherthanscrolling.-d........--dumbDumbterminal.-Dxcolor.--color=xcolorSetscreencolors.-e-E....--quit-at-eof--QUIT-AT-EOFQuitatendoffile.-f........--forceForceopennon-regularfiles.-F........--quit-if-one-screenQuitifentirefilefitsonfirstscreen.-g........--hilite-searchHighlightonlylastmatchforsearches.-G........--HILITE-SEARCHDon't highlight any matches for searches.-h[N]....--max-back-scroll=[N]Backwardscrolllimit.-i........--ignore-caseIgnorecaseinsearchesthatdonotcontainuppercase.-I........--IGNORE-CASEIgnorecaseinallsearches.-j[N]....--jump-target=[N]Screenpositionoftargetlines.-J........--status-columnDisplayastatuscolumnatleftedgeofscreen.-k[file].--lesskey-file=[file]Usealesskeyfile.-K........--quit-on-intrExitlessinresponsetoctrl-C.-L........--no-lessopenIgnoretheLESSOPENenvironmentvariable.-m-M....--long-prompt--LONG-PROMPTSetpromptstyle.-n-N....--line-numbers--LINE-NUMBERSDon't use line numbers.-o[file].--log-file=[file]Copytologfile(standardinputonly).-O[file].--LOG-FILE=[file]Copytologfile(unconditionallyoverwrite).-p[pattern]--pattern=[pattern]Startatpattern(fromcommandline).-P[prompt]--prompt=[prompt]Definenewprompt.-q-Q....--quiet--QUIET--silent--SILENTQuiettheterminalbell.-r-R....--raw-control-chars--RAW-CONTROL-CHARSOutput"raw"controlcharacters.-s........--squeeze-blank-linesSqueezemultipleblanklines.-S........--chop-long-linesChop(truncate)longlinesratherthanwrapping.-t[tag]..--tag=[tag]Findatag.-T[tagsfile]--tag-file=[tagsfile]Useanalternatetagsfile.-u-U....--underline-special--UNDERLINE-SPECIALChangehandlingofbackspaces.-V........--versionDisplaytheversionnumberof"less".-w........--hilite-unreadHighlightfirstnewlineafterforward-screen.-W........--HILITE-UNREADHighlightfirstnewlineafteranyforwardmovement.-x[N[,...]]--tabs=[N[,...]]Settabstops.-X........--no-initDon't use termcap init/deinit strings.-y[N]....--max-forw-scroll=[N]Forwardscrolllimit.-z[N]....--window=[N]Setsizeofwindow.-" [c[c]]  .  --quotes=[c[c]]Setshellquotecharacters.-~........--tildeDon't display tildes after end of file.-# [N]  ....  --shift=[N]Sethorizontalscrollamount(0=onehalfscreenwidth).--follow-nameTheFcommandchangesfilesiftheinputfileisrenamed.--incsearchSearchfileaseachpatterncharacteristypedin.--line-num-width=NSetthewidthofthe-NlinenumberfieldtoNcharacters.--mouseEnablemouseinput.--no-keypadDon't send termcap keypad init/deinit strings.--no-histdupsRemoveduplicatesfromcommandhistory.--rscroll=CSetthecharacterusedtomarktruncatedlines.--save-marksRetainmarksacrossinvocationsofless.--status-col-width=NSetthewidthofthe-JstatuscolumntoNcharacters.--use-backslashSubsequentoptionsusebackslashasescapechar.--use-colorEnablescoloredtext.--wheel-lines=NEachclickofthemousewheelmovesNlines.---------------------------------------------------------------------------LINEEDITINGThesekeyscanbeusedtoedittextbeingenteredonthe"command line"atthebottomofthescreen.RightArrow.....................ESC-l...Movecursorrightonecharacter.LeftArrow......................ESC-h...Movecursorleftonecharacter.ctrl-RightArrowESC-RightArrowESC-w...Movecursorrightoneword.ctrl-LeftArrowESC-LeftArrowESC-b...Movecursorleftoneword.HOME...........................ESC-0...Movecursortostartofline.END............................ESC-$...Movecursortoendofline.BACKSPACE................................Deletechartoleftofcursor.DELETE.........................ESC-x...Deletecharundercursor.ctrl-BACKSPACEESC-BACKSPACE...........Deletewordtoleftofcursor.ctrl-DELETE....ESC-DELETE....ESC-X...Deletewordundercursor.ctrl-U.........ESC(MS-DOSonly).......Deleteentireline.UpArrow........................ESC-k...Retrievepreviouscommandline.DownArrow......................ESC-j...Retrievenextcommandline.TAB......................................Completefilename&cycle.SHIFT-TAB......................ESC-TABCompletefilename&reversecycle.ctrl-L...................................Completefilename,listall.

more+3test.txt