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
Putin on Terror Threats and the Tuapse Situation
President Putin emphasized rising terrorist threats, accusing Kyiv and its backers of resorting to terrorism amid frontline setbacks. He cited the recent strike on energy facilities in Tuapse, highlighting potential environmental risks. Despite this, the situation remains under control, with local services effectively managing the challenges. Following Putin’s orders, the Emergency Ministry head has arrived to coordinate response efforts.
#Putin#Tuapse#Terrorism#Ukraine#Emergencies
The main news of Russia and the world ishere.
Heavy Rain Disrupts Power Supply in Ingushetia and Chechnya
Severe downpours have caused power and water outages in Ingushetia cities—Karabulak, Nazran, and Sunzha. Specialists are working to fix faults in electrical grids and pumping stations. Similar disruptions affect some Chechen districts due to rain and wind.
“Several areas in Karabulak are experiencing electricity interruptions caused by heavy rainfall,” local authorities reported.
#Ingushetia#Chechnya#Weather#PowerOutage#Emergencies
The main news of Russia and the world ishere.
The fifth season of the International Prize #WEARETOGETHER has been launched.
▫️ Foreign citizens and NGOs can apply until June 23, 2025 on the official website of the Prize https://wearetogetherprize.com.
🌐 The Prize is available for volunteers and NGOs from across the globe. The laureates will receive a cash prize valued at $10,000 and an invitation to take part in the International Forum of Civil Participation #WEARETOGETHER, which is traditionally held in December in Moscow.
👉🏻 Prize nominations:
♻️“Sustainable Future”
For those who are leading projects in the field of environmental protection, environmental education, ecological consumption, “green” economy and technologies
#ecology#urbanism#biodiversity#recycling#environmental protection
🕊️“Human Assistance”
For those who run projects aimed at improving the well-being of vulnerable categories of citizens, providing social and humanitarian assistance to people, discovering talents and nurturing individuals, developing education and volunteerism.
▫️ Apply here: https://wearetogetherprize.com/
#social_help#medicine#donorship#healthcare#emergencies
🔜The fifth season of the International Prize #WEARETOGETHER has been launched. Foreign citizens and NGOs can apply until June 23, 2025 on the official website of the Prize.
The Prize is available for volunteers and NGOs from across the globe. The laureates will receive a cash prize valued at $10,000 and an invitation to take part in the International Forum of Civil Participation #WEARETOGETHER, which is traditionally held in December in Moscow.
Prize nominations:
✔️“Sustainable Future”
For those who are leading projects in the field of environmental protection, environmental education, ecological consumption, “green” economy and technologies
#ecology#urbanism#biodiversity#recycling#environmental protection
✔️ “Human Assistance”
For those who run projects aimed at improving the well-being of vulnerable categories of citizens, providing social and humanitarian assistance to people, discovering talents and nurturing individuals, developing education and volunteerism.
Apply here
#social_help#medicine#donorship#healthcare#emergencies