Jerin RHCSA: Yadda Ake Gudanar da Fayil da Gudanarwa - Sashe na 2

A cikin wannan labarin, RHCSA Sashe na 2: Fayil da sarrafa kundin adireshi, za mu sake nazarin wasu mahimman ƙwarewa waɗanda ake buƙata a cikin ayyukan yau da kullun na mai gudanar da tsarin.

Ƙirƙiri, Share, Kwafi, da Matsar da Fayiloli da kundayen adireshi

Gudanar da fayil da kundin adireshi muhimmin ƙwarewa ne wanda kowane mai gudanar da tsarin yakamata ya mallaka. Wannan ya haɗa da ikon ƙirƙirar/share fayilolin rubutu daga karce (tushen tsarin kowane shiri) da kundayen adireshi (inda zaku tsara fayiloli da sauran kundayen adireshi), da kuma gano nau'in fayilolin da ke akwai.

Ana iya amfani da umarnin taɓawa ba kawai don ƙirƙirar fayilolin da ba komai ba, har ma don sabunta damar shiga da lokutan gyare-gyare na fayilolin data kasance.

Kuna iya amfani da fayil [filename] don tantance nau'in fayil (wannan zai zo da amfani kafin ƙaddamar da editan rubutu da kuka fi so don gyara shi).

da rm [filename] don share shi.

Dangane da kundayen adireshi, zaku iya ƙirƙirar kundayen adireshi a cikin hanyoyin da ake da su tare da mkdir [directory] ko ƙirƙirar cikakkiyar hanya tare da mkdir -p [/full/path/to/directory].

Idan ya zo ga cire kundayen adireshi, kuna buƙatar tabbatar da cewa babu komai kafin a ba da umarnin rmdir [directory], ko amfani da mafi ƙarfi (a kula da kulawa!) rm -rf [directory] . Wannan zaɓi na ƙarshe zai tilasta cirewa akai-akai [directory] da duk abin da ke cikinsa - don haka yi amfani da shi cikin haɗarin ku.

Mayar da Input da Fitarwa da Bututun Mai

Yanayin layin umarni yana ba da fasali guda biyu masu fa'ida waɗanda ke ba da damar tura shigarwa da fitarwa na umarni daga fayiloli da fayiloli, da aika fitar da umarni zuwa wani, wanda ake kira redirection da pipelining, bi da bi.

Don fahimtar waɗannan mahimman ra'ayoyi guda biyu, dole ne mu fara fahimtar nau'ikan rafukan I/O (Input da Output) mafi mahimmanci guda uku (ko jerin) haruffa, waɗanda a haƙiƙanin fayiloli ne na musamman, a *nix ma'anar kalmar.

  1. Standard shigarwar (aka stdin) ta tsohuwa an haɗa shi da madannai. A wasu kalmomi, madannai shine daidaitaccen na'urar shigarwa don shigar da umarni zuwa layin umarni.
  2. Standard fitarwa (aka stdout) ta tsohuwa an haɗa shi da allon, na'urar da karɓi fitar da umarni da nuna su akan allon.
  3. Standard error (aka stderr), shine inda ake aika saƙonnin matsayi ta hanyar tsohuwa, wanda kuma shine allon.

A cikin misali mai zuwa, ana aika fitarwa na ls/var zuwa stdout (allon), da kuma sakamakon ls /tecmint. Amma a cikin yanayin ƙarshe, stderr ne aka nuna.

Don samun sauƙin gano waɗannan fayiloli na musamman, an ba wa kowannensu bayanin bayanin fayil, wakilcin da ake amfani da shi don samun damar su. Muhimmin abu don fahimta shine waɗannan fayilolin, kamar sauran, ana iya tura su. Abin da wannan ke nufi shi ne, za ku iya ɗaukar abubuwan da aka fitar daga fayil ko rubutun kuma aika shi azaman shigarwa zuwa wani fayil, umarni, ko rubutun. Wannan zai ba ku damar adanawa akan faifai, misali, fitar da umarni don sarrafawa ko bincike daga baya.

Don tura stdin (fd 0), stdout (fd 1), ko stderr (fd 2), akwai masu aiki masu zuwa.

Sabanin juyar da kai, ana yin bututun bututun ta hanyar ƙara sandar tsaye (|) bayan umarni da kuma gaban wani.

Ka tuna:

  1. Ana amfani da jujjuyawa don aika fitarwar umarni zuwa fayil, ko don aika fayil azaman shigar da umarni.
  2. Ana amfani da bututun bututu don aika fitar da umarni zuwa wani umarni azaman shigarwa.

Akwai lokutan da za ku buƙaci sake maimaita lissafin fayiloli. Don yin hakan, zaku iya fara ajiye wannan jeri zuwa fayil sannan ku karanta layin fayil ɗin ta layi. Duk da yake gaskiya ne cewa zaku iya maimaita kan fitar da ls kai tsaye, wannan misalin yana nuna alamar juyawa.

# ls -1 /var/mail > mail.txt

Idan muna son hana duka stdout da stderr su nuna akan allon, za mu iya tura duka sifofin fayilolin zuwa /dev/null. Lura yadda fitarwa ke canzawa lokacin da aka aiwatar da juyawa don umarni iri ɗaya.

# ls /var /tecmint
# ls /var/ /tecmint &> /dev/null

Yayin da classic syntax na cat umurnin ne kamar haka.

# cat [file(s)]

Hakanan zaka iya aika fayil azaman shigarwa, ta amfani da madaidaicin afaretan juyawa.

# cat < mail.txt

Idan kuna da babban kundin adireshi ko lissafin tsari kuma kuna son samun damar gano takamaiman fayil ko tsari a kallo, zaku so bututun jeri zuwa grep.

Lura cewa muna amfani da bututu a cikin misali mai zuwa. Na farko yana neman kalmar da ake buƙata, yayin da na biyu zai kawar da ainihin umarnin grep daga sakamakon. Wannan misalin yana lissafin duk matakan da ke da alaƙa da mai amfani da apache.

# ps -ef | grep apache | grep -v grep