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
*FRACTION OF SECONDS*
Woke up. I knew I was late. Coz that was my routine. And coz of a simple logic, why be excited to wake up early and go to a place you hate and do something that you hate!
I sighed when my mouth tasted coffee before colgate...Ahh! how I love normal days, It was a normal day. At least that's what I thought. Papa was there looking up from the newspaper at me with a sense of pity.
I sort of ignored that and walked out through the front door, but the next sight, a brand new beautiful ladybird and an even more beautiful rider, with short black hair waving in the wind, in a skirt that knew well not to cover her beautiful legs... Well I couldn't ignore that! Just a fraction of seconds and I had already captured her. Made her mine. Is this what they call...
Oops!! She looked at me. Damn it! She caught me staring at her! I looked away whistling. I looked again, did I see a smile?
I heard Mom shouting my name out aloud. I knew I had to rush. As I was rushing inside I heard a loud thud. I turned back and saw the beautiful ladybird lying on the road. It was only a fraction of second, yet my mind talked to me in infinite speed...Somethings...what did he say I don't remember anymore. I remember rushing back to the house.
One year I didn't talk to our new neighbour who was an year older than me.Days went by. Mom had started packing things up one evening I came back from school. Papa received his transfer letter.
Now whenever I see a cycle I think. What would've happened? Why hadn't I stopped my mind talking to me? Why hadn't I I rushed 'out'side than 'in'side? All in a fraction of second!
#JOHN PAUL BENOY
#Review
*FRACTION OF SECONDS*
Woke up. I knew I was late. Coz that was my routine. And coz of a simple logic, why be excited to wake up early and go to a place you hate and do something that you hate!
I sighed when my mouth tasted coffee before colgate...Ahh! how I love normal days, It was a normal day. At least that's what I thought. Papa was there looking up from the newspaper at me with a sense of pity.
I sort of ignored that and walked out through the front door, but the next sight, a brand new beautiful ladybird and an even more beautiful rider, with short black hair waving in the wind, in a skirt that knew well not to cover her beautiful legs... Well I couldn't ignore that! Just a fraction of seconds and I had already captured her. Made her mine. Is this what they call...
Oops!! She looked at me. Damn it! She caught me staring at her! I looked away whistling. I looked again, did I see a smile?
I heard Mom shouting my name out aloud. I knew I had to rush. As I was rushing inside I heard a loud thud. I turned back and saw the beautiful ladybird lying on the road. It was only a fraction of second, yet my mind talked to me in infinite speed...Somethings...what did he say I don't remember anymore. I remember rushing back to the house.
One year I didn't talk to our new neighbour who was an year older than me.Days went by. Mom had started packing things up one evening I came back from school. Papa received his transfer letter.
Now whenever I see a cycle I think. What would've happened? Why hadn't I stopped my mind talking to me? Why hadn't I I rushed 'out'side than 'in'side? All in a fraction of second!
#JOHN PAUL BENOY
#Review
#short story
Former US National Security Advisor John Bolton:
“Although you could potentially remove the ayatollah, that would leave the IRGC in place, and the government in Iran is the IRGC, while the ayatollahs act as a religious cover or an ideological cover for them.
I think Trump is just hoping that this show of American power will intimidate the ayatollahs. If I were still his adviser, I would be happy to tell him that it won’t work.
They won’t be intimidated. But Trump really thinks minute by minute; he doesn’t think strategically.”
#john#bolton#trump#ayatollah
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