The 1 denotes standard output (stdout). The 2 denotes standard error (stderr). So 2>&1 says to send standard error to where ever standard output is being redirected as well.
Ithini intsingiselo ka-2 >&1?
“Usebenzisa &1 ukubhekisa kwixabiso lesichazi sefayile 1 (stdout). Ke xa usebenzisa i-2>&1 ngokusisiseko uthi "Khombisa kwakhona i-stderr kwindawo enye sikwalathisa kwakhona i-stdout". Yiyo loo nto sinokwenza into enje ukuqondisa kwakhona zombini i-stdout kunye ne-stderr kwindawo enye:
What does 2 >& 1 mean and when is it typically used?
&1 is used to reference the value of the file descriptor 1 (stdout). Now to the point 2>&1 means “Redirect the stderr to the same place we are redirecting the stdout”
Yintoni i$$ kwiLinux?
$$ yinkqubo ye-ID (PID) yeskripthi ngokwaso. I-$BASHPID yinkqubo ye-ID yemeko yangoku yeBash. Oku akufani nokwahluka kwe-$$, kodwa ihlala inika iziphumo ezifanayo. https://unix.stackexchange.com/questions/291570/what-is-in-bash/291577#291577. Yabelana.
Uthetha ukuthini u-2 kwiLinux?
2 ibhekisa kwisichazi sefayile yesibini yenkqubo, okt stderr . > kuthetha ukuhanjiswa. &1 ithetha into ekujoliswe kuyo yolawulo ngokutsha kufuneka ibe yindawo enye njengenkcazo yefayile yokuqala, okt stdout .
Ngaba 1.5 ithetha enye enesiqingatha?
Ibinzana lesiNgesi elithi "isiqingatha esinye" lithetha isiqingatha - ngokufutshane, i-0.5 ngexabiso. … Isiqingatha esinye sisiqingatha, okanye 0.5 . Inye enesiqingatha yi 1.5.
Ithetha ntoni i-1 kumyalezo obhaliweyo?
interjection. “goodbye”. I’ll talk to you later.
Ndiyisalathisa njani ngokutsha stderr?
Isiphumo esiqhelekileyo sithunyelwa kwi-Standard Out (STDOUT) kwaye imiyalezo yephutha ithunyelwa kwi-Standard Error (STDERR). Xa uthumela kwakhona imveliso yeconsole usebenzisa i > isimboli, uthumela kwakhona iSTDOUT. Ukuze uphinde uqondise i-STDERR, kufuneka uchaze u-2> kwisimboli yokwalathisa ngokutsha.
Usebenzisa ntoni ukuthumela iimpazamo kwifayile?
Iimpendulo ze2
- Qondisa kwakhona i-stdout kwifayile enye kunye ne-stderr kwenye ifayile: umyalelo> ngaphandle kwe-2>impazamo.
- Qondisa kwakhona i-stdout kwifayile ( > ngaphandle ), kwaye emva koko uqondise kwakhona i-stderr kwi-stdout ( 2>&1 ): umyalelo > ngaphandle 2>&1.
What is $? In Bash?
$? lutshintsho olukhethekileyo kwi-bash ehlala ibamba ikhowudi yokubuya/yokuphuma yomyalelo wokugqibela owenziweyo. Ungayijonga kwi-terminal ngokusebenzisa i-echo $? . Iikhowudi zokubuya zikuluhlu [0; 255]. Ikhowudi yokubuya engu-0 idla ngokuthetha ukuba yonke into ilungile.
Yintoni $1 kwi Linux?
$1 yingxoxo yokuqala yomgca womyalelo egqithiselwe kwiskripthi seqokobhe. … $0 ligama lombhalo ngokwawo (script.sh) $1 yimpikiswano yokuqala (igama lefayile1) $2 yimpikiswano yesibini (dir1)
Yintoni ukusetyenziswa kweLinux?
I '!' isimboli okanye umqhubi kwiLinux angasetyenziswa njengomsebenzi wokuLala ngokuQingqiweyo kunye nokulanda imiyalelo kwimbali ngokulungiswa okanye ukusebenzisa umyalelo owenziwe ngaphambili ngoguqulelo.
Ndilazi njani iqokobhe lam langoku?
Indlela yokukhangela ukuba leliphi iqokobhe endilisebenzisayo: Sebenzisa le miyalelo ilandelayo yeLinux okanye yeUnix: ps -p $$ – Bonisa igama lakho langoku leqokobhe ngokuthembekileyo. echo "$SHELL" - Shicilela iqokobhe lomsebenzisi wangoku kodwa hayi iqokobhe elisebenzayo kwintshukumo.
Yintoni i-$? Kwi Unix?
$? -Imo yokuphuma yomyalelo wokugqibela owenziweyo. $0 -Igama lefayile yoshicilelo lwangoku. $# -Inani leengxoxo ezinikezelweyo kwiscript. $$ -Inani lenkqubo yeqokobhe langoku. Kwiqokobhe lemibhalo eshicilelweyo, le yinkqubo ye-ID apho baphumeza khona.
Ngowuphi umyalelo okuvumela ukuba ujonge yonke imiyalelo oyisebenzisileyo?
Kwi Linux, kukho umyalelo oluncedo kakhulu wokukubonisa yonke imiyalelo yokugqibela esandula kusetyenziswa. Umyalelo ubizwa nje ngokuba yimbali, kodwa unokufikelelwa ngokujonga eyakho . bash_history kwifolda yakho yasekhaya.
What does stdout mean?
I-Stdout, eyaziwa ngokuba yimveliso eqhelekileyo, yinkcazo yefayile engagqibekanga apho inkqubo inokubhala imveliso. Kwiinkqubo zokusebenza ezifana ne-Unix, ezifana ne-Linux, i-macOS X, kunye ne-BSD, i-stdout ichazwa ngumgangatho we-POSIX. Inombolo yenkcazo yefayile engagqibekanga ngu-1. Kwi-terminal, imveliso esemgangathweni iyagqibeka kwiscreen somsebenzisi.