TGINSIGHT SIMILAR POSTS
Изворен канал @pythonotes · Post #411 · 9 фев.
reload_flag="" if [[ -n "${DEBUG}" ]]; then reload_flag="--reload" fi if [[ -n "${WORKER_COUNT}" ]]; then workers=${WORKER_COUNT} else workers=2 fi gunicorn --workers ${workers} \ --bind 0.0.0.0:8000 \ ${reload_flag} main.wsgi Писали такие конструкции чтобы проверить наличие флага и сформировать команду правильно? На самом деле можно сделать тоже самое проще. Для этого используются операторы условной подстановки, доступные в оболочках семейства POSIX. :- для установки значений по умолчанию ${WORKER_COUNT:-2} Если переменная не объявлена, то будет дефолтное значение 2. :+ подставляет указанный текст, если переменная не пуста ${DEBUG:+--reload} Если что-то есть в переменной то распечатается текст после символа +, в противном случае - ничего. Удобно для опциональных флагов, как в нашем примере. Итого наш скрипт может выглядеть так: gunicorn --workers ${WORKER_COUNT:-2} \ --bind 0.0.0.0:8000 \ ${DEBUG:+--reload} main.wsgi Есть еще два оператора. := не только подставить дефолтное значение, но и присвоить его переменной, если она пуста # никаких переменных еще нет VAL1=${VAL2:=hello} # теперь доступны обе echo $VAL1 $VAL2 # hello hello :? остановить выполнение с ошибкой, если переменной нет. echo ${MISS:?is required} bash: MISS: is required Код выхода будет 1. #tricks#linux
Пребарај: #sgweathergrams
@NEASingapore · Post #589 · 12.07.2023 г., 01:02
Did you manage to catch these pastel-coloured altocumulus clouds at sunset? When the sun is at a low angle on the horizon, sunlight travels across a longer distance through the atmosphere before reaching our eyes. As a result, blue colours are scattered by atmospheric particles, leaving behind brilliant hues of pink, orange and yellow. 📷: peiqiitohh #SGWeathergrams#WeatherWednesday
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@NEASingapore · Post #565 · 14.06.2023 г., 00:31
If you were in the Newton area on 25 May, you may have spotted this huge woolly blanket in the sky! This blanket of dense clouds was formed as the top of a cumulonimbus cloud collapsed following strong thunderstorms across Singapore earlier that morning. Named “cirrus spissatus”, these rarer upper atmosphere clouds are thicker and denser, and would block out the sun. The Latin word “spissatus” in its name describes its thicker appearance. 📷 Photo by _quietude__ #SGWeathergrams#WeatherWednesday
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@NEASingapore · Post #78 · 15.07.2020 г., 00:30
The mesmerising patterns formed by these beautiful stratocumulus clouds, seem to be reminding us to keep a safe distance from each other as we go about our daily activities. Tag us in your #SGWeathergrams on Instagram so that we can share your beautiful captures with others! #WeatherWednesday 📷: infectiousj
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@NEASingapore · Post #105 · 22.09.2020 г., 07:45
Hello Halo! Did you spot it this afternoon? These faint coloured rings encircling the sun are formed by the refraction of the light through ice crystals in high-level clouds under relatively clear conditions. #SGWeathergrams#SGWeather
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@NEASingapore · Post #90 · 12.08.2020 г., 00:30
While an impending thunderstorm looms, blue skies and fluffy clouds shine through in the distance. Tag us in your #SGWeathergrams posts on Facebook & Instagram so we can share it on #WeatherWednesdays. :) 📷: siewjunjie
@NEASingapore · Post #579 · 05.07.2023 г., 01:01
#WeatherWednesday#throwback to the sunrise on 17 Jun, when we were greeted by this beautiful scattering of cirrocumulus stratiformis clouds. The Latin word “stratiformis” means “stretched out”, referring to its irregular, dotted, blanket-like appearance. 📷 Photo by knifematchneedle #SGWeathergrams