Mmene Mungagwiritsire ntchito "bc" Calculator mu Scripts

Pulogalamu ya Linux bc ikhoza kugwiritsidwa ntchito ngati pulogalamu yamakono yabwino kapena ngati chilankhulo cha masamu. Ndi zophweka ngati kuitanitsa bc lamulo kupyolera otsiriza.

Kuwonjezera pa bc, bungwe la Bash limapereka njira zina zochepa zogwiritsira ntchito masamu .

Zindikirani: Pulogalamu ya bc imatchedwanso basic calculator kapena bench calculator.

bc Lamulo la Syntax

Mawu omasuliridwa a bc command ali ofanana ndi chinenero cha C, ndipo ogwira ntchito zosiyanasiyana amathandizidwa, monga kuwonjezera, kuchotsa, kuphatikiza kapena kuchepetsa, ndi zina.

Izi ndizosintha zosiyanasiyana zomwe zili ndi bc lamulo:

• -h, --help: Akujambula kugwiritsa ntchito ndi kutuluka.
• -i, - osagwiritsidwa ntchito: Maofesi oyanjanitsa.
• -l, --mathlib: Gwiritsani ntchito masewero oyambirira a masamu.
• -q, --quiet: Sakusindikiza banner yoyamba.
• -s, - yosungirako: Osagwirizana ndi bc kumanga ndi zolakwika.
• -w, - Dziwani: Amachenjeza za osakhala ofanana BC yomanga.
• -v, --version: kusindikiza mauthenga ndi kutuluka.

Onani bc Lamulo la Mauthenga kuti mudziwe zambiri za momwe mungagwiritsire ntchito makina oyambirira.

bc lamulo chitsanzo

Choyimira chogwiritsira ntchito chingagwiritsidwe ntchito mu chithokomiro mwa kungowalowa bc , pambuyo pake mungathe kulembetsa mafupipafupi mazenera monga awa:

4 + 3

... kuti mupeze zotsatira monga izi:

7

Pochita mawerengedwe angapo mobwerezabwereza, ndizomveka kugwiritsa ntchito bc calculator ngati gawo la script. Maonekedwe ophweka kwambiri a script angawoneke monga chonchi:

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

Mzere woyamba ndi njira yokha yomwe ikugwiritsira ntchito script.

Mzere wachiwiri uli ndi malamulo awiri. Lamulo lolembera limapanga chingwe chomwe chiri ndi mawu a masamu omwe ali m'mawu amodzi (6.5 ogawanika ndi 2.7, mu chitsanzo ichi). Woyendetsa bomba (|) amapereka chingwe ichi ngati kutsutsana kwa pulogalamu ya bc. Kuchokera kwa pulogalamu ya bc ndikuwonetsedwa pa mzere wa lamulo.

Kuti muyese seweroli, mutsegule zenera zowonongeka ndikuyendetsa kumalo omwe muli script. Titha kuganiza kuti fayilo ya script imatchedwa bc_script.sh . Onetsetsani kuti fayilo ikugwiritsidwa ntchito pogwiritsa ntchito lamulo la chmod :

chmod 755 bc_script.sh

Ndiye mukanalowa:

./bc_script.sh

Zotsatira zake zidzakhala zotsatirazi:

2

Pofuna kusonyeza malo 3 decimal chifukwa yankho lolondola ndi 2.407407 ..., gwiritsani ntchito mawu ochepa mkati mwachingwe chomwe chinatchulidwa ndi ndemanga imodzi:

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

Kuti muwerenge bwino, mzere ndi ziwerengero zingathe kulembedwa pamzere wambiri. Kuti muwononge mzere wa mzere mu mizere yambiri yomwe mungayimbenso kubwerera kumapeto kwa mzere:

Echo 'scale = 3; var1 = 6.5 / 2.7; var1 '\ | bc

Kuti muphatikize mfundo zowonjezera mzere mu mawerengedwe anu a bc, muyenera kusintha ndemanga imodzi pamagwero awiri kuti zizindikiro za mzere wa lamulo zimasulidwe ndi chipolopolo cha Bash:

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

Mtsutso woyamba wa mzere wotsogoleredwa ukupezeka pogwiritsa ntchito "$ 1", chigwirizano chachiwiri chimagwiritsa ntchito "$ 2", ndi zina zotero.

Tsopano mukhoza kulembera zolemba zanu zokhazikika pamabuku osiyana a Bash ndi kuwaitanira ku malemba ena.

Mwachitsanzo, ngati script1 ili ndi:

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

... ndipo script2 ili ndi

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

... kenako kuchita script2 kudzapempha script1 pogwiritsa ntchito variable $ fres yolembedwa mu script2 ngati parameter.