Indlela yokusebenzisa i-"bc" Calculator ku-Scripts

Uhlelo lwe-Linux bc lungasetshenziswa njengendlela yokubala yedeskithophu elula noma njengelulwimi lokubhala isazi. Kulula njengokubiza umyalo we- bc ngokusebenzisa ukuphela.

Ngaphandle kwesevisi ye-bc, igobolondo le-Bash linikeza ezinye izindlela ezimbalwa zokwenza imisebenzi yezibalo .

Qaphela: Uhlelo lwe-bc lubizwa nangokuthi i-calculator eyisisekelo noma ibhenki yokubala.

bc i-Syntax yoMyalo

I- syntax yomyalo we-bc ifana nolimi lwezinhlelo ze-C, futhi ama-operators ahlukahlukene asekelwa, njengokungeza, ukususa, ukuhlanganisa noma ukunciphisa, nokuningi.

Lezi yizitshalo ezihlukahlukene ezitholakala ngomyalo we-bc:

• -h, --help: Iphrinta lokhu ukusetshenziswa futhi iphuma.
• -i, - engasebenzi: Imodi yokusebenzisana yamaForces.
• -l, -mathlib: Sebenzisa ama-math routini.
• -q, --quiet: Awuphrinti ibhanna yokuqala.
• -s, i-standard: Izakhiwo ezingezona ezejwayelekile ze-bc amaphutha.
• -w, - funda: Ixwayisa mayelana nokwakhiwa kwe-bc okungavamile.
• -v, --version: ulwazi lwenguqulo ye-Prints nokuphuma.

Bheka le Bc Manual Manual ukuze uthole imininingwane eyengeziwe mayelana nokuthi ungasebenzisa kanjani i-calculator eyisisekelo.

Bc Isibonelo Isiyalo

I-calculator eyisisekelo ingasetshenziswa esiphethweni ngokungena nje ku- bc , ngemva kwalokho ungatheyipha izinkulumo zezibalo ezifana nalokhu:

4 + 3

... ukuthola umphumela onjengale:

7

Uma wenza uchungechunge lwezibalo ngokuphindaphindiwe, kunengqondo ukusebenzisa i-calculator ye-bc njengengxenye yeskripthi. Ifomu elilula le script elinjalo lingabheka into enjengale:

#! / bin / bash echo '6.5 / 2.7' | bc

Umzila wokuqala uwukuphela kwendlela ephumelelayo egijima le script.

Umugqa wesibili uqukethe imiyalo emibili. Umyalo we- echo ukhiqiza uchungechunge oluqukethe inkulumo yezibalo eziqukethe izingcaphuno ezilodwa (6.5 ehlukaniswe ngu-2.7, kulesi sibonelo). Umqhubi wephayiphi (|) udlulisa lolu chungechunge njengengxabano ohlelweni lwe-bc. Okukhipha uhlelo lwe-bc ke kuboniswa emgqeni wokulalelwayo.

Ukuze ukhiphe le script, vula iwindi elibulalayo bese uhamba uye esiqondisweni lapho iskripthi sitholakala khona. Sizocabanga ukuthi ifayela leskripthi libizwa ngokuthi i-bc_script.sh . Qinisekisa ukuthi ifayela lisebenza ngokusebenzisa umyalo we- chmod :

chmod 755 bc_script.sh

Khona-ke ungangena:

./bc_script.sh

Umphumela uzoba okulandelayo:

2

Ukuze ubonise izindawo ezingu-3 zedesimali kusukela impendulo yangempela ngu-2.407407 ..., sebenzisa isitatimende esikalini ngaphakathi kwochungechunge olukhishwe yizicatshulwa ezilodwa:

#! / bin / bash echo 'scale = 3; 6.5 / 2.7 '| bc

Ukuze ufunde kahle, umugqa ngezibalo ungabhalwa kabusha emigqeni eminingi. Ukuze uphule umugqa womyalo ube imigqa eminingi ungafaka ukubuyela emuva ekupheleni komugqa:

u-echo 'scale = 3; var1 = 6.5 / 2.7; var1 '\ | bc

Ukufaka iziphakamiso zomugqa womyalo kumanani akho we-bc, kufanele ushintshe izingcaphuno ezilodwa zibe izingcaphuno ezimbili ukuze amatshwayo wepharamitha womugqa womyalo ahunyushwa ngegobolondo le-Bash:

beka "isikali = 3; var1 = 6.5 / 2.7; var2 = 14 * var1; var2 * = $ 1; var2" \ | bc

Umcibisholo wokuqala womugqa womyalo ufinyelelwe usebenzisa ukuguquguquka "$ 1", ingxabano yesibili isebenzisa i- "$ 2", njll.

Manje ungabhala imisebenzi yakho ye-arithmetic eyenziwe ngezikripthi ezihlukile zeBash bese uyibiza kusuka kwezinye izikripthi.

Isibonelo, uma iskripthi1 iqukethe:

#! / bin / bash echo "scale = 3; var1 = 6.5 / 2.7; var2 = 14 * var1; var2 * = $ 1; var2" \ | bc

... futhi i-script2 iqukethe

#! / bin / bash var0 = "100" echo "var0: $ var0" umsebenzi fun1 {echo "scale = 3; var1 = 10; var2 = var1 * $ var0; var2" \ | bc} fres = $ (fun1) echo "fres:" $ fres var10 = $ (./ script1 $ fres); beka "var10:" $ var10;

... bese ukwenza script2 kuzofaka isicelo script1 besebenzisa i-variable $ fres ebhaliwe script2 njengepharamitha.