Sauya Sauyawa Mai Canjawa da Ƙararren BASH Variables a cikin Linux - Kashi na 11

Labari biyu na ƙarshe akan BASH Shell, inda muka tattauna dalla-dalla dalla-dalla an yaba sosai tsakanin masu karatunmu. Mu a matsayin Tecmint-Team muna da sha'awar samar muku da Sabbin Sabbin abubuwa, Na yau da kullun da batutuwa masu dacewa da aka rufe da cikakkun bayanai. Bugu da ƙari, koyaushe muna ƙoƙarin taɓa manyan ra'ayoyi na batutuwan da suka dace.

Anan shine labarin ƙarshe akan Linux Variables inda zamu ga canji da masu canji da aka ayyana a cikin Shell kafin rufe wannan batu.

Bash yana yin canjin canji kafin a aiwatar da umarni da gaske. Linux Bash Shell yana neman duk alamar ''$' kafin aiwatar da umarnin kuma ya maye gurbinsa da ƙimar mabambanta. Ana aiwatar da tsarin sauya Bash Variable sau ɗaya kawai. Idan muna da masu canji fa?

Lura: Ta wurin madaidaicin gida muna nufin, m bayyananne a cikin m. Bari mu ga yanayin da ke sama a cikin misalin da ke ƙasa.

Ƙayyade madaidaicin wanda shine Karanta-Kawai kuma Ana iya aiwatarwa kamar ƙasa.

[email :~$ declare -rx Linux_best_website="linux-console.net"

Bincika ƙimar maɓalli da aka adana.

[email :~$ printf "%s" "$Linux_best_website" 

linux-console.net

Yanzu ayyana wani canji wanda kuma shine Karanta-kawai kuma Mai aiwatarwa.

[email :~$ declare -rx Linux_website="Linux_best_website"

Yanzu halin da ake ciki shi ne, mun ayyana masu canji guda biyu.

'Linux_best_website', wanda darajarsa shine \linux-console.net
da, 'Linux_website', wanda darajarsa shine \Linux_best_website

Menene sakamakon, idan muka gudanar da umarnin layi ɗaya na ƙasa?

[email :~$ printf "%s" "$Linux_website"

Ya kamata a fara maye gurbin m '$Linux_website', tare da darajar \Linux_best_website sa'an nan kuma \$Linux_best_website ya sake zama mai canzawa. darajar wadda ita ce \linux-console.net Don haka ya kamata fitowar karshe ta gudanar da umarnin da ke ƙasa ya kasance.

[email :~$ printf "%s" "$Linux_website" 

linux-console.net

Amma abin takaici, ba haka lamarin yake ba, abin da muke samu shine Linux_best_website.

Dalili? Ee! Bash ya musanya darajar ma'auni sau ɗaya kawai. Me game da hadaddun rubutun da shirye-shirye inda muke buƙatar musanya masu canji akai-akai da kuma buƙatar musanya canjin fiye da sau ɗaya?

Anan ya zo da umarnin '' eval' wanda ke yin ƙarin aiki na canji fiye da sau ɗaya a cikin rubutun. Anan akwai misali don sanya duka aiki a sarari kamar gilashi.

Ƙayyade m x, wanda darajarsa ita ce 10.

[email :~/Desktop$ declare x=10

Duba ƙimar m x, kawai mun ayyana.

[email :~/Desktop$ echo $yx

x10

Ƙayyade m y, wanda ƙimarsa shine x.

[email :~/Desktop$ declare y=x

Duba ƙimar m y, kawai mun ayyana.

[email :~/Desktop$ echo $y 

x

Ga matsalar BASH sauyi sau ɗaya, wanda baya yin ƙarin zagaye na canji. Muna amfani da 'eval' umarni don gyara wannan.

[email :~/Desktop$ eval y=$x

Yanzu duba ƙimar m'y'.

[email :~/Desktop$ echo $y 

10

Hura! An daidaita batun kuma umurnin 'eval' ya lashe tseren :)

Ba a ma maganar ba, ‘eval’ umarni yana da taimako sosai a cikin manyan shirye-shiryen rubutun kuma kayan aiki ne mai amfani sosai.

Ƙarshe amma ba ƙaramin ɓangaren wannan post ɗin ba shine sauye-sauyen da aka riga aka ƙayyade na BASH. A'a! Kada ku ji tsoro ganin wannan jerin. Ba kwa buƙatar tunawa da jerin duka kafin ku fara rubuta rubutun sai kaɗan. A matsayin wani ɓangare na tsarin ilmantarwa, muna gabatar da BASH da aka riga aka ayyana jeri.

Akwai babban jerin abubuwan da aka riga aka ƙayyade BASH Variable. Mun yi ƙoƙarin samar da jerin mafi yawan amfani da su.

Shi ke nan a yanzu. Zan sake kasancewa a nan tare da wani labari mai ban sha'awa. Har sai a saurara kuma ku haɗa zuwa TecMint. Kar ku manta da samar mana da ra'ayoyin ku masu mahimmanci a cikin sashin sharhin da ke ƙasa.