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
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👩🏻🚀💄: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #SpaceShip called " Minji Moodboard " from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #Awäa💄. Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀💄: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #SpaceShip called " Yunjin Moodboard " from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #Awäa💄. Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀💄: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #SpaceShip called " Go Younjung MoodBoard" from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #Awäa💄. Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀💄: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #SpaceShip called " Eunchae Moodstagram " from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #Awäa💄. Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀💄: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #SpaceShip called " Lia MoodBoard " from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #Awäa💄. Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀💄: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #SpaceShip called " Hanni Moodstagram " from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #Awäa l. Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀💄: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #SpaceShip called "Yunjin MoodBoard " from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #Awäa💄. Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀🌧: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #Spaceship called "Rose" from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #revaya . Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀🌧: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #Spaceship called "Hueningkai" from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #revaya . Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)
👩🏻🚀🌧: *𝗕𝗢𝗢𝗠* 🤯🤯 Woah 😵💫😵... What was that 🤔🤔? Its was a super-duper big *boom* 💥💥 that just come to our 𝗯𝗲𝗮𝘂𝘁𝗶𝗳𝘂𝗹 𝗺𝗼𝗼𝗻 🌑🌕, and look. They giving us a super-duper adorable 𝗽𝗮𝗰𝗸𝗮𝗴𝗲 📦📦, lets check it now! Ooh 😯😯, its a #Spaceship called "Kyujin" from our 𝗳𝗿𝗶𝗲𝗻𝗱𝘀 👨👩👧👦, which is #revaya . Ah, thank you @moonivrse lets check the licence first! Oh, its only for PU (Personal Use)