Indlela yokongeza izibalo kwiSkripthi seBash
Nangona i-Bash yintetho yeskripthi, inamathuba amaninzi kuwo onke amanqanaba okusetyenziswa kolwimi lwenkqubo jikelele. Oku kubandakanya imisebenzi ye-arithmetic. Kukho iinketho ze- syntax ongazisebenzisayo ukuvandlakanya ukuhlolwa kwe-arithmetic yegama. Mhlawumbi ofundeka kakhulu ngumyalelo wokuvumela. Umzekelo
vumela "m = 4 * 1024"Uya kuqulunqa amaxesha angama-4 1024 kwaye anike umphumo kwi-variable "m".
Ungaprintela umphumo ngokufaka ingxelo ye- echo :
vumela "m = 4 * 1024" i-$ mUnokuvavanya oku ukusuka kumgca womyalelo ngokufaka ikhowudi elandelayo:
vumela "m = 4 * 1024"; u-$ mUnokwenza kwakhona ifayile equlethe imiyalelo yeBash, kwimeko apho kufuneka udibanise umgca phezulu kwefayili ecacisa inkqubo ekufuneka iyenze ikhowudi. Umzekelo:
#! / bin / bash bashhi "m = 4 * 1024" u-$ mUkucinga ukuba i-Bash ephumelelayo ikhona kwi / bin / bash . Kwakhona kufuneka ubeke iimvume zefayili yakho yeskripthi ukuze iphumeze. Ukucinga ukuba igama lefayile yeskripthi script1.sh , ungasetha iimvume ukwenza ifayile isebenze ngomyalelo:
chmod 777 script1.shEmva koko unokwenza ngayo umyalelo:
./script1.shImisebenzi ye-arithmetic ekhoyo ifana nalawo kwiilwimi eziqhelekileyo zokusetyenziswa njengeJava kunye noCC Ngaphandle kokuphindaphinda, njengoko kuboniswe ngasentla, usebenzisa okubongeziweyo:
vumela "m = a + 7"okanye ukususa:
vumela "m = a-7"okanye ukwahlula:
vumela "m = a / 2"okanye i-modulo (intsalela emva kwesahlulo se-integer):
vumela "m = i% 100"Xa usebenziso lusetyenziselwa kwisitshixo esifanayo apho isiphumo sinikwe khona ungasebenzisa i-arithematic standard shorthand operators, ekubhekiselwe kuzo njengabasebenzi abenzileyo. Umzekelo, ukongeza, sinakho:
vumela "m + = 15"elilingana ne "m = m + 15". Ukukhupha sinakho:
vumela "m - = 3"elilingana ne "m = m-3". Ukwahlukana esinalo:
vumela "m / = 5"elilingana ne "m = m / 5". Kwaye nge-modulo, sinakho:
vumela "m% = 10"elilingana ne "m = m% 10".
Ukongezelela, unokusebenzisa abasebenzisi bokunyusa kunye nokunciphisa :
vumela "m ++"lilingana ne "m = m + 1". Kwaye
vumela "m--"lilingana ne "m = m - 1".
Kwaye kukho i-ternary "mark mark-colon" yomsebenzisi wee-ternary, ebuyisela enye yexabiso elibini kuxhomekeke ekubeni ingaba imeko echanileyo iyinyani okanye iyinyani. Umzekelo
vumela "k = (m <9)? 0: 1"Icandelo lesandla sokunene sesitatimende sabelo sihlola "0" ukuba iinguqulelo "m" ingaphantsi kwe-9. Ngaphandle koko, ivavanya kwi-1. Oku kuthetha ukuba inguquko "k" ibelwe "0" ukuba "m" ingaphantsi ngaphaya kwe-9 kwaye "1" kungenjalo.
Ifom ejwayelekile yomqhubi-umbuzo we-colon ngu:
imeko? xabiso-xa-yinyaniso: xabiso-xa-inkohlisoI-Arithmetic ye-Floating Point eBash
Umsebenzisi ovumelekileyo usebenza kuphela kwi-arithmetic eninzi. I-arithmetic enefuthe enokuthi ungayisebenzisa umzekelo i-calculator ye-GNU bc njengoko kuboniswe kulo mzekelo:
phendula "32.0 + 1.4" | bcUmqhubi "umbhobho" "|" idlula igama elithi "32.0 + 1.4" kwi-calculator ye-bc, ebuyisela inombolo yangempela. Umyalelo we- echo uprinsa umphumo kwisiphumo esisezantsi.
I-Syntax enye yeArithmetic
Iimbuyiselo (izicatshulwa ezingasemva) zingasetyenziselwa ukuphonononga ibinzana le-arithmetic njengale mzekelo:
phendula i-expr $ m + 18`Oku kuya kwandisa 18 kwixabiso le variable "m" uze uprinte umphumo.
Ukunika ixabiso lokubala kwi-variable ukuba ungasebenzisa uphawu olulinganayo ngaphandle kweendawo ezikujikelezile:
m = `expr $ m + 18`Enye indlela yokuvavanya amagama ase-arithmetic ukusebenzisa abazali ababini. Umzekelo:
((m * = 4))Oku kuya kukhangela ixabiso le-variable "m".
Ngaphandle kokuvavanya i-arithmetic, igobolondo yeBash inikeza ezinye iinkqubo zokwakha, ezifana ne -loops , ngelixa-loops , iimeko kunye nemisebenzi kunye neenkomfa .