Marcel - Morearin Shell na zamani don Linux

Lura cewa pi an yi aiki da shi. Gabaɗaya, marcel yana amfani da yara don iyakance maganganun Python. Don haka (pi) yana kimanta furucin Python wanda zai dawo da ƙimar pi mai canji. Hakanan zaka iya samun damar sauyin yanayi na al'ada ta wannan hanyar, misali. (MAI AMFANI) da (HOME), ko kowane ingantaccen furucin Python dogaro da alamomi a cikin jerin sunayen marcel.

Kuma zaku iya, ba shakka, ayyana alamunku. Misali, idan ka sanya ma'anar wannan aikin a cikin ~/.marcel.py :

def factorial(n):
    f = 1
    for i in range(1, n + 1):
        f *= i
    return f

to, zaku iya amfani da aikin gaskiyar akan layin umarni, misali.

Marcel Shell Misalai

Anan, zamu koya wasu misalai na umarni a cikin harsashin marcel.

Bincika kundin adireshi na yanzu a sake dawowa, tara fayilolin ta hanyar fadada su (misali .txt , .py da sauransu), kuma lissafa girman fayil ɗin kowane rukuni.

Kuna iya yin wannan a cikin marcel kamar haka:

Mai aikin ls yana samar da kwararar abubuwan Fayil, ( -fr na nufin ziyartar kundin adireshi akai-akai, kuma dawo da fayiloli kawai).

Ana saka abubuwa na Fayil zuwa umarni na gaba, taswira. Taswirar tana ayyana aikin Python, a cikin ƙananan iyaye, wanda ke taswira kowane fayil zuwa ƙuƙwalwar da ke ɗauke da fayel, kuma girmanta ne. (Marcel yana ba da damar cire kalmar lambda.)

Mai jan (rage), ƙungiyoyi ta ɓangaren farko na ƙara (tsawaita) sannan kuma ya taƙaita girman a cikin kowane rukuni. An tsara sakamakon ta tsawo.

Bututun ruwa na iya ƙunsar cakuda masu sarrafa marcel da masu gudanar da aiki. Masu aiki suna bututun abubuwa, amma a iyakar mai aiki/aiwatarwa, maɓallin bututun marcel maimakon.

Misali, wannan umarnin ya hada masu aiki da aiwatarwa kuma ya lissafa sunayen masu amfani na masu amfani wanda harsashi yake /bin/bash .

$ cat /etc/passwd \
| map (line: line.split(':')) \
| select (*line: line[-1] == '/bin/bash') \
| map (*line: line[0]) \
| xargs echo

cat ne mai aiwatar da Linux. Yana karanta/sauransu/passwd, kuma marcel bututun abubuwan da ke ciki zuwa ƙasa zuwa taswirar mai sarrafa marcel.

Maganar mahaifa don taswira aiki ne na Python wanda ke raba layuka a : masu raba, suna samar da 7-tuples. Zaɓi shine mai ba da labari wanda hujjarsa aikin Python ce ta gano waɗancan tuples ɗin waɗanda filin ƙarshe shine/bin/bash.

Mai aiki na gaba, wani taswira yana riƙe filin sunan mai amfani na kowane ƙaramin abu. Aƙarshe, xargs echo ya haɗu da sunayen masu amfani masu shigowa zuwa layi ɗaya, wanda aka buga zuwa tsayi.

Rubutu a cikin Marcel Shell

Duk da yake Python wani lokacin ana ɗaukarsa a matsayin yaren rubutun, ba ya yin aiki da kyau don wannan dalilin. Matsalar ita ce yin umarnin harsashi, da sauran masu aiwatarwa daga Python yana da wahala. Kuna iya amfani da os.system() , wanda yake da sauƙi amma sau da yawa bai dace ba don ma'amala da stdin, stdout, da stderr. subprocess.Popen() yafi karfi amma yafi hadadden amfani.

Hanyar Marcel shine don samar da ƙirar da ke haɗa masu sarrafa marcel tare da fasalin yaren Python. Don sake duba misali na baya, ga lambar Python don ƙididdige jimlar girman fayiloli ta ƙari:

from marcel.api import *

for ext, size in (ls(file=True, recursive=True)
                  | map(lambda f: (f.suffix, f.size))
                  | red('.', '+')):
    print(f'{ext}: {size})

Umurnin harsashi iri ɗaya ne da na da, banda taron ƙira. Don haka ls -fr ya juya zuwa ls (fayil = Gaskiya, recursive = Gaskiya). Taswirar da masu jan aiki suna wurin ma, an haɗa su da bututu, kamar yadda yake a cikin fasalin harsashi. Dukkanin umarnin kwasfa (ls… ja) yana samar da mai karanta Python saboda a iya amfani da umarnin tare da Python's don madauki.

Samun Bayanan Bayanai tare da Marcel Shell

Kuna iya haɗa hanyoyin samun bayanai tare da bututun marcel. Da farko, kuna buƙatar saita hanyar samun bayanai a cikin fayil ɗin daidaitawa, ~/.marcel.py , misali

define_db(name='jao',
          driver='psycopg2',
          dbname='acme',
          user='jao')

DB_DEFAULT = 'jao'

Wannan yana daidaita damar zuwa gidan yanar gizon Postgres mai suna acme, ta amfani da direba na psycopg2. Za a yi haɗi daga marcel ta amfani da mai amfani da jao, kuma sunan mai bayanan bayanan suna jao. (DB_DEFAULT ya ƙayyade bayanan bayanan jao a matsayin wanda za a yi amfani da shi idan ba a bayyana bayanin martaba ba.) Tare da wannan daidaitaccen aikin da aka yi, yanzu ana iya tambayar bayanan ta amfani da sql operator, misali

sql 'select part_name, quantity from part where quantity < 10' \
| out --csv –-file ~/reorder.csv

Wannan umarnin yana tambayar tebur mai suna sashi, kuma yana jefa sakamakon tambaya a cikin fayil ɗin ~/reorder.csv , a cikin tsarin CSV.

Samun Nesa tare da Marcel Shell

Hakanan don samun damar bayanai, damar nesa za a iya saita shi cikin ~/.marcel.py . Misali, wannan yana daidaita tarin -node 4-node:

define_remote(name='lab',
              user='frankenstein',
              identity='/home/frankenstein/.ssh/id_rsa',
              host=['10.0.0.100', 
                    '10.0.0.101',
                    '10.0.0.102',
                    '10.0.0.103'])

Za a iya gano gungu a matsayin lab a cikin umarnin marcel. Mai amfani da sigogin asali sun ƙayyade bayanin shiga, kuma sashin mai gabatarwar ya ƙayyade adiresoshin IP na nodes ɗin a kan gungu.

Da zarar an daidaita gungu, duk nodes za a iya aiki sau ɗaya. Misali, don samun jerin pids na aiwatarwa da layin umarni a fadin tarin:

@lab [ps | map (proc: (proc.pid, proc.commandline))]

Wannan yana dawo da rafin (adireshin IP, PID, layin umarni) tuples.

Don ƙarin bayani ziyarci:

• https://www.marceltheshell.org/
• https://github.com/geophile/marcel

Marcel ya kasance sabon sabo kuma yana ƙarƙashin ci gaba mai aiki. Samu lamba idan kanaso a taimaka.