А знаете ли вы, что в Bash есть особая переменная "$_" ? Из описания можно узнать, что в переменную "$_" помещается последний аргумент последней команды.
Что-то знакомое? Конечно, в Python есть примерно тоже самое.
Мы знаем, что дата первого релиза Bash (8 июня 1989) несколько раньше чем первый релиз Python (20 февраля 1991). Если учесть, что по задумке автора Python это агрегация самых успешных практик отовсюду, можно ли сказать что именно эта фишка к нему пришла из Bash? Ни подтверждения ни опровержения я пока не нашел.
Давайте просто считать это совпадением 😉
А как это может быть полезно в Bash?
Приведу простой пример, который оценят те, кто часто работает в терминале.
Допустим, нам надо создать директорию и зайти в неё. Что обычно делаем?
:~$ mkdir foldername
:~$ cd foldername
:~/foldername$
Как это сделать в одну команду?
:~$ mkdir foldername && cd foldername
:~/foldername$
Уже лучше, но хочется короче, без повторов. Вот тут и пригодится наша переменная. Напомню, что в неё сохраняется последний аргумент предыдущей команды.
:~$ mkdir foldername && cd $_
:~/foldername$
_________________
PS.
Символы "&&"" разделяют команды и означают, что требуется выполнить вторую команду только если первая завершилась успешно.
#linux#tricks
Why am i so addled, i seek retort through this creation.
Can't understand a thing, anymore. I just need Salvation
What am i gonna gain, if anything, why do i need revelation.
I do just fine without mass, getting back to isolation?
Why is it so important, why look for identification?
Is it the curiosity or the fear of seperation?
There is inspiration, there is recreation, there is manipulation, sensation, violation & frustration but is there anything that's necessary? Is there any elevation?
I know it bothers none but please, tell me, where am i heading to, what is my destination?
#Snowy#review
I mutilate myself, no matter what i do.
Acting all spirit, i maim when I'm disregarded, when I'm passed over.
Acting all foul isn't my cup of tea either, i maim again, i incapacitate either way.
Being ignoble and or moral, both roads are noxious to me. What do i fancy then?
You blemish me, your bygones. I can't condone it. I can't strand you either. You, your, it impedes me, candidly but won't gash you by disclaim, renounce.... Won't? Well, can't is more apt, can't bestow to soar your agony.... But about my torment? I have nowhere to go, no door left open, I'm stuck, stuck with you. I'll dwell, I'll persist, that's what I've been doing, that's what i can keep up with. No possibility, either at whim or reluctantly, i have to adhere, no recourse.... I'd be thrusting here, i don't know the stretch, the extent, maybe perpetuity.
#review#Snowy
Why am i so addled, i seek retort through this creation.
Can't understand a thing, anymore. I just need Salvation
What am i gonna gain, if anything, why do i need revelation.
I do just fine without mass, getting back to isolation?
Why is it so important, why look for identification?
Is it the curiosity or the fear of seperation?
There is inspiration, there is recreation, there is manipulation, sensation, violation & frustration but is there anything that's necessary? Is there any elevation?
I know it bothers none but please, tell me, where am i heading to, what is my destination?
#Snowy#review
You were fire, i wasn't ice
I was supposed to but it wasn't nice
I was magma that was piquant
Why was our bond so highly turbulent?
The violent gesticulation of air around your flames
Wasn't any good for my fever but i got used to the games
We were bonded the way we weren't meant to be
Was it destiny, i wondered or was it our will that was the key
You're no good for me, i know, said she
But it was too late for her to be set in the world again like a bird, free
If we're meant to do it together, yes my love, we suffer like the way we suffered
You'd be the flame of my candle that demolishes my wax, he uttered
Afterall, diamonds dice diamonds, they are suited together
Shouldn't be befuddled with types different but stay where they belong, forever
#Snowy
#review