Iko kushandiswa kweS $ SHLVL inoshandiswa kukutaurira kuti ingani mahombekombe akadzika iwe uri. Kana iwe uchivhiringidzika neizvi zvakakodzera kutanga pakutanga.
Shell Chii?
A shell inotora mirairo uye inovapa iyo inoshanda yehurongwa hwekuita. Pamatunhu akawanda e Linux purogiramu yekorodhe inonzi BASH (The Bourne Again Shell) asi kune mamwe anowanikwa kusanganisira C Shell (tcsh) neKORN shell (ksh).
Nzira Yokuwana Sei Linux Shell
Kazhinji semushandisi waunosangana nawo nehurongwa weklobho kuburikidza nekushandiswa kwegadziriro yekugadzirisa kwekupedzisira seXTerm, konsole kana gnome-terminal.
Kana iwe uri kutarisa fenenenenhenji yakadai seWorboxbox kana kuti nzvimbo yepakombiyuta yakadai seGNOME kana KDE iwe uchawana muteveri emulator zvimwe kubva kumenyu kana dashi. Pamaitiro akawanda nzira shoma yeCTRL ALT uye T ichazarura firati yekuguma.
Zvichida iwe unogona kuchinja kune imwe tty (teletypewriter) iyo inopa kuwanikwa zvakananga kumutemo wemirazi shell. Iwe unogona kuita izvi nekudhinda CTRL ALT uye F1 kana CTRL ALT uye F2 nezvimwe.
Shell Level Chii?
Paunenge uchitanga murairo muhomwe iyo inomhanya pane chimwe chinhu chinonzi shell level. Pakati pehombe iwe unogona kuzarura imwe shell inoita kuti ive soro kana shell yakaizarura.
Nokudaro chikwata chemubereki chaizotaridzirwa zvichida sezinga 1 shell uye mwana wekombe ingadai iri yezinga 2 shell.
Nzira Yokuratidzira Nayo Shell Level
Inofanira kuuya sekusashamisika zvichienderana nezita rehurukuro iyo nzira yaunogona kutaura nayo iyo imwe yero yezinga iwe uri kushanda nayo iri kushandisa shanduro ye $ SHLVL.
Kuti uone huwandu hwema shell iwe ikozvino huri kuronga muchirongwa zvinotevera:
echo $ SHLVL
Pane kufarira kana iwe uchimhanya murairo wepamusoro mukati mewindo rekupedzisira unogona kushamisika kuona kuti mhinduro yakadzoka ndeye 2.
Kana zvakadaro iwe unomhanya murairo wakafanana uchishandisa tty saka chigumisiro chacho ndechekutanga.
Sei izvi zvichiitika iwe ungabvunza? Zvakanaka dhidhiyo yemhepo yauri kushanda iri kumhanya pamusoro pebhokisi. Iko ganda raizova chiyero 1. Chero firiji rekugadzirisa raunotanga kubva mukati memhepo yakadzika midzi iyo inofanira kuva mwana weiyo shell yakazarura mamiriro ezvikiti uye naizvozvo chikwata chekanda hachikwanisi kutanga pane imwe nhamba imwe kunze kwe 2.
Nyaya haisi kuendesa nzvimbo yekodzero uye saka inongova yezinga 1 shell.
Nzira Yokugadzira Subshells
Nzira iri nyore yekuedza nayo pfungwa yeholls uye subshells ndeyotevera. Vhura bhenekeri hwindo uye ugoita zvinotevera:
echo $ SHLVL
Sezvatinoziva kubva pawindo rekugadzirisa huwandu hunofu huwandu huno 2.
Iye zvino mukati memagetsi ewindo fomu inotevera:
sh
Murairo wekushanda pachake unotanga ganda rinopindirana rinoreva kuti uri kushandisa shell mukati mehombe kana pasi.
Kana iwe zvino faira iyi zvakare:
echo $ SHLVL
Iwe uchaona kuti chikwata chekorodhe chakasarudzwa kusvika ku 3. Running the command sh kubva mukati me subsell ichazarura shanduro ye subshell uye saka chikwata chego shell chichava pachikwata chechina.
Nei Chirongwa cheShell Chikosha?
Nhamba yekororo inokosha apo iwe uchifunga nezvehuwandu hwezvimwe zviri mukati mezvinyorwa zvako.
Ngatitange nechinhu chakareruka:
Imbwa = maisie
echo $ mbwa
Kana iwe uchimhanya murairo wepamusoro muhomwe shoko maisie richaratidzwa kune firati yekupedzisira.
Vhura shell itsva nekunyora zvinotevera:
sh
Kana iwe uchitanga murairo uyu iwe uchaona kuti hapana chaidzorerwa zvakare:
echo $ mbwa
Izvozvo ndezvekuti dollar inoshandiswa inowanika chete pahomwe yezinga 2. Kana iwe uchinyorera kubuda kuti ubudise shanduro uye unomhanya echo $ imbwa zvakare shoko maisie richaratidzwa zvakare.
Zvakakoshawo kufungisisa pamusoro pemafambiro emhando dzakasiyana-siyana mukati me shell.
Tanga pane imwe firati inotara uye funga zvinotevera:
export dog = maisie
echo $ mbwa
Sezvaungatarisira shoko rokuti maisie rinoratidzwa. Iye zvino vhura gorosi uye firidzira echo $ imbwa zvakare. Panguva ino iwe uchaona kuti shoko maisie rinoratidzwa kunyange iwe uri mune shandiro.
Chikonzero cheizvi ndechokuti mutemo wekutengesa wakaita kuti imbwa yemadhora ishanduke pasi rose. Kushandura imbwa yemadhora kunoshandiswa mukati me subshell kunyange kana iwe ukashandisa mutemo wekutumira hauna kuchinja pamakanda ayo emubereki.
Tine tariro kubva pane izvi unogona kuona kuti kuziva chikwata chekushanda iwe uri kushanda kune chimwe chinhu chinokosha pakunyora zvinyorwa.
Mienzaniso yandakapa ndiyo yakanyanyisa kunzwisisa asi yakajairika pane imwe script script kudana imwe shell script iyo inoshevedza imwe script script yose iyo ikozvino inoshanda kumatanho akasiyana. Kuziva hutachiona hunove hunokosha zvikuru.