Ho ea ka Wikipedia, metacharacter ke motho ea nang le moelelo o khethehileng, o kang carat (^), letšoao la dollar ($) kapa asterisk (*).
Mabapi le Linux, ho na le palo e nepahetseng ea li-metacharacters le litlhaloso tsa tsona li fapana ho latela litaelo kapa lenaneo leo u le sebelisang.
Full Stop Joaloka Metacharacter (.)
Sebaka se seng se le seng sa boikokobetso se sebelisetsoa ho fana ka boemo ba hona joale ha ho etsoa litaelo tse kang cd , fumana kapa sh empa ka hare ho likopo tse kang awk , grep le sed e sebelisetsoa ho hlalosa motho ofe kapa ofe.
Ka mohlala, taelo e latelang e tla fumana lifaele tsohle tsa mp3 fensetereng ea hona joale le ka tlase.
fumana. -name * .mp3
Haeba u tsamaisa taelo eo ho uena ho hlahisa buka ea ho sebetsa (pwd) ka nako eo u tla fumana liphello tse khutlisitsoeng, ho nka hore u boloka lifaele tsa hau tsa mp3 meleng ea 'mino ka har'a fensetere ea lapeng.
Joale sheba taelo ena:
ps -ef | grep f..efox
Pora ea litaelo e thathamisa mekhoa eohle e sebetsang ea khomphuta ea hau. Taelo ea grep e nka mela ea ho kenya le lipatlisiso bakeng sa mohlala.
Ka lebaka leo, polelo ea ps -ef e fumana lethathamo la mekhoa e sebetsang 'me e e fa grep e batlang le lengolo le leng lethathamong le nang le ffox. e ka bolela motho leha e le ofe.
Haeba u na le firefox e mathang u tla fumana papali. Ka tsela e ts'oanang, haeba o na le lenaneo le bitsoang fonefox kapa freefox e tla boela le khutlisetsoe.
Asterisk e le metacharacter (*)
Asterisk ke metacharacter e tummeng ka hohle-hohle 'me e sebelisetsoa ho bolela 0 kapa ho feta ha e batla mokhoa.
Ka mohlala:
fumana. -name * .mp3
The * .mp3 khutlisetsa papali bakeng sa filename efe kapa efe e qetellang ka .mp3. Ka mokhoa o ts'oanang, nka be ke sebelisitse asterisk ka taelo ea grep joalokaha tse latelang li bontša:
ps -ef | grep F * efox
Ke habohlokoa hore re hlokomele hore sena se fapana hanyane hobane asterisk e bolela zero kapa ho feta le ho fumana firefox, facefox le fonefox e ka boela ea fumana flutefox, ferretfox esita le fefox feela.
Carat e le Metacharacter (^)
Carat (^) e sebelisetsoa ho hlalosa qalo ea mola kapa khoele. Joale ho sebelisoa joang?
Taelo ea ls e sebelisoa ho thathamisa lifaele tsohle foleng ka tsela e latelang:
ls
Haeba o batla ho tseba lifaele tsohle fokoleng e qalang ka mohala o itseng o kang "gnome" ebe carat e ka sebelisoa ho hlalosa khoele eo.
Ka mohlala:
ls | grep ^ gnome
Hlokomela hore sena se feela se thathamisa lifaele tse qalang ka bonyane. Haeba u batla lifaele tse nang le letšoao le hlabang ka lebitso la mohala kae kapa kae moo u ka khutlelang ho asterisk hape.
Mohlala o ka holimo, ls e khutlisetsa lethathamo la li-file le li-passes tse thathamisang ho grep e sebelisetsoang mokhoa oa ho bapisa. grep oa tseba hore letšoao la carat le bolela ho fumana ntho leha e le efe e qalang ka litlhaku tse tlang ka morao ho eona 'me tabeng ena, ke ntho e monate.
Dollar Symbol e le Metacharacter ($)
Letšoao la dollar le na le litlhaloso tse ngata joaloka metacharacter ka hare ho Linux.
Ha e sebelisetsoa ho bapisa mekhoa e bolela se fapaneng le carat mme e hlalosa mohlala ofe kapa ofe o qetellang ka mohala o itseng.
Ka mohlala:
ls | grep png $
Sena se thathamisa lifaele tsohle tse qetellang ka png.
Letšoao la dollar le boetse le sebelisetsoa ho fumana mefuta e sa tšoaneng ea tikoloho ka har'a shell ea bash.
Ka mohlala:
ntja ea thepa = molly
echo ea dollar
Ntja ea thepa ea ho romela mekhoa = molly e baka mocha o fapaneng o bitsoang ntja 'me o beha bohlokoa ba oona ho molly. Ho fihlella tikoloho ho fapana le $ symbol e sebelisoa. Ka $ symbol echo $ dollar statement e bontša molly empa ntle le eona, polelo ea polelo ea ntja e bontša feela ntja lentsoe.
Ho baleha metacharacters
Ka linako tse ling ha u batle hore metacharacter e be le moelelo o khethehileng. Ho thoe'ng haeba u na le faele e bitsoang f.refox le faele e bitsoang firefox.
Joale shebang taelo e latelang:
ls | grep f.refox
U nahana hore u khutlisetsoa eng? Ka bobeli f.refox le firefox li khutlisetsoa hobane li li bapisa le mohlala.
Ho khutlisa f.refox feela u tla hloka ho baleha seteishene se feletseng ho bolela ho ema ka ho feletseng ka tsela e latelang:
ls | grep f \\. refox
Li-Metacharacters Tse Tloaelehileng le Tlhaloso ea Bona
| Boemo | Sehlooho |
| . | Mofuta ofe kapa ofe |
| * | Zero kapa litlhaku tse ngata |
| ^ | Tlanya line kapa mohala o qalang ka mohlala (ke hore ... o motsoako) |
| $ | Tlanya line kapa khoele e qetellang ka mohlala (e leng $ gnome) |
| \ | O baleha moetapele o latelang ho tlosa moelelo oa oona o khethehileng |
| [] | Tlanya lethathamo le leng le le leng (ie, "abc", "def"] kapa [1..9] |
| + | Bapisa e le 'ngoe kapa tse ling tse fetileng (ie grep a +) |
| ? | Nako ea ho bapala kapa ea pele |