Kuxazululiwe: ungabheka kanjani ukuthi ifayela likhona lua

Impela, nakhu okusalungiswa kwesihloko sakho:

Ukuqonda amandla nokuguquguquka kwezinhlelo ze-Lua kunikeza inani elibalulekile lokuphatha amafayela ngendlela enobuhlakani. Isici esisodwa esibalulekile okufanele siphawulwe yikhono layo lokuhlola ukuthi ifayela likhona yini. Lokhu kusebenza kubaluleke kakhulu ekugwemeni amaphutha noma imiphumela engahlosiwe ngesikhathi sokusebenza kwefayela. Namuhla, sihlose ukuhlukanisa inqubo yokuqinisekisa ubukhona befayela sisebenzisa i-Lua.

local fileExists = function(filename)
    local file = io.open(filename, "r")
    if file == nil then 
        return false 
    else 
        file:close() 
        return true 
    end 
end

Lolu cezu olulula lwekhodi lusiza ukucacisa ubukhona befayela. Isebenzisa izinga lika-Lua I-IO Library ukuvula ifayela kwimodi yokufunda, futhi uma ifayela lingakwazi ukuvulwa, kusho ukuthi ifayela alikho futhi umsebenzi uyabuya. bamanga. Ngokuphambene, uma ifayela livulwe ngempumelelo, liyavalwa ngokushesha ukuze kuvinjwe ukuvuza kwensiza futhi umsebenzi uyabuya. weqiniso.

Ukwephula Ifayela Le-Lua Likhona Hlola

Ake sijule ekuqondeni ukuthi isisombululo sisebenza kanjani.

Okokuqala, sichaza umsebenzi - ifayelaExists. Lo msebenzi uthola ipharamitha eyodwa, okuyigama lefayela - ifayela esihlose ukuliqinisekisa ukuthi likhona.

Okulandelayo, umsebenzi uvula ifayela nge io.vula umsebenzi usebenzisa i 'r' (funda) ipharamitha.

Ngemva kwalokho, elula uma-okunye ukuvimba okunemibandela kuyaqaliswa. Uma umphumela we io.vula ucingo lilingana ne nil, umsebenzi ubuyisela okungamanga, okusho ukuthi ifayela alikho. Uma kungenjalo (ifayela litholakele), umsebenzi uvala ifayela nge- ifayela:vala shayela, ukuphatha kahle izinsiza, futhi ubuyisela iqiniso.

Iqhaza Lemitapo yolwazi ye-Lua ekusebenzeni kwefayela

Izinsiza ze-Lua, njenge- I-IO Library futhi I-OS Library, zibe nesandla ekuqaliseni ukusebenza kwefayela.

Ngokukhethekile, i I-IO Library inikeza io.vula umsebenzi osetshenziswe kusixazululo sethu. Lo msebenzi wenza imizamo yokuvula ifayela usebenzisa igama lefayela elinikeziwe elinemodi eshiwo ('r' kithi).

Ukwengeza, i io.vala umsebenzi, ovela kumtapo wolwazi ofanayo, usivumela ukuthi sikhulule izinsiza zesistimu ngemva kokuvula ifayela ngempumelelo.

Sengiphetha, ukuba nekhono ekuphatheni amafayela nge-Lua kuvula izwe lamathuba. Kungakhathaliseki ukuthi wakha izinhlelo zesofthiwe eziyinkimbinkimbi, noma wenza imisebenzi elula yokukhohlisa amafayela, imitapo yolwazi enamandla ye-Lua namathuluzi akunikeza ukusebenza kahle okudingayo.

Khumbula, amandla amahle ngokusebenza kwefayela lika-Lua akukwenzi nje kuphela umthuthukisi ongcono kodwa futhi kwenza inqubo yakho yokuxazulula izinkinga ibe lula.

Okuthunyelwe okuhlobene:

Shiya amazwana