Bash Ki Te-Kete Tauākī Me Nga Tauira

Mena-kaore he korero i roto i te tuhi tuhi bash he rite ki etahi atu reo whakamahere; he tikanga hei whakatau kaupapa ma te hotaka.

Kei if-else tauākī, te whakatinanatanga o te poraka tauākī ka whakatauhia i runga i te otinga o te if huru



Bash Ki Te-Kete Tauākī Kupu Whakahoki

Te wetereo o te if-else tauākī i bash ko:


if [condition] then
//if block code else // else block code fi

Mena ka aromatawaihia te ahuatanga ki true, te if ka mahia he waehere poraka, ana mena ka aromatawaihia te ahua ki false katahi te else ka mahia te waehere poraka.

Panui:Ko te aukati anake ka whakamatea mena ka aromatawai te ahuatanga ki pono .
Ko te korero ke me era atu poraka waehere he kowhiringa.

Me whakaoti e maatau te if tauākī me te fi kupu matua




Whakataurite Herenga

Ko te rerenga e whakamahia ana e te herenga herenga hei aromatawai i tetahi true ko false. Ko te whakahua he aho kotahi, he taurangi ranei.

  • iti iho i te - tohua e: $a -lt $b ko $a < $b
  • nui atu i - tohua e: $a -gt $b ko $a > $b
  • iti iho i te rite ranei ki - tohua e: $a -le $b ko $a <= $b
  • nui ake i te orite ranei ki - tohua e: $a -ge $b ko $a >= $b
  • ōrite ki - tohua e: $a -eq $b ko $a == $b
  • kaore e rite ki - tohua e: $a -ne $b ko $a != $b

Nga Kaituku Arorau

Ko te korero i roto i te if ko te tauākī ka taea te whakakotahitanga arorau o ngā whakataurite maha.

Ko nga kaiwhakahaere whaitake ko:

  • arorau me - tohua e $a AND $b ko $a && $b arotake ki te true ina he pono nga taurangi, nga korero ranei.
  • arorau ranei - tohua e $a OR $b ko $a || $b arotake ki te true ina he pono tetahi o nga taurangi, korero ranei.
Panui:I a koe e whakamahi ana i nga kaiwhakahaere arorau, me karapoti nga whaikikotanga herenga e nga taiapa takirua [[]].

Hei tauira:


#!/bin/bash first_name='John' last_name='Doe' if [[ $first_name = 'John' && $last_name = 'Doe' ]] then echo 'hello John Doe' fi

Bash mena he Tauira

Ko te if he tauākī ohie noa te tauākī. Mena te ahuatanga kei roto i te if[] arotake ki te true katahi te if ka mahia te poraka waehere.

Tauira:

#!/bin/bash read -p 'Enter a number: ' mynumber if [ $mynumber -gt 10 ] then
echo 'The number you entered is greater than 10' fi
Panui:I roto i te tauira o runga ake nei, mena ka whakauruhia e maatau tetahi nama e iti ake ana i te 10, kaare he mea ka taarua.

Bash mena ka-kore Tauira

I te otinga o te if ko te huru he _ _ _ _. katahi te waehere kei te false ka mahia he poraka, mena tera ano tetahi.

Hei tauira:


else

Bash if-elif-atu Tauira

Ko te #!/bin/bash read -p 'Enter a number: ' mynumber if [ $mynumber -gt 10 ] then
echo 'The number you entered is greater than 10' else
echo 'The number you entered is less than 10' fi
(ka kore mena) ka whakamahia ina he maha elif tikanga.

Hei tauira:

if

Bash Whakanohoia mena he Tauira

Ka taea hoki e tatou te ohanga #!/bin/bash read -p 'Enter your exam grade: ' grade if [ $grade -ge 80 ] then
echo 'You got A' elif [ $grade -ge 70 ] then
echo 'You got B' elif [ $grade -ge 60 ] then
echo 'You got C' else
echo 'Fail' fi
tauākī.

Hei tauira:


if