Revisions to Check for process and kill if running

made note that [ is a bash builtin and not directly related to `man test` I suggested

Source Link

edited Jul 13, 2016 at 9:19

1.3k
10
9

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
to run a program and put its output into a variable, you need $(...) (preferred in bash, not available in sh) or backticks `command` (supported in bash and sh). (and remember that when assigning a variable, quotes are not needed, but in other cases they are important: command "$(command)")

wrong:
```
  APP_ID=command
```
right:
```
  APP_ID=$(command)
```
add spaces around everything when using "[", and you need a semicolon or newline after the "]". This is because "[" is a bash builtin command, and the non-builtin one is also known as "test" (see man test), which just like other commands, takes its arguments separated by space:

wrong:
```
  if[x!= y] then echo hello world fi
```
right:
```
  if [ x != y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
to run a program and put its output into a variable, you need $(...) (preferred in bash, not available in sh) or backticks `command` (supported in bash and sh). (and remember that when assigning a variable, quotes are not needed, but in other cases they are important: command "$(command)")

wrong:
```
  APP_ID=command
```
right:
```
  APP_ID=$(command)
```
add spaces around everything when using "[", and you need a semicolon or newline after the "]". This is because "[" is a command also known as "test" (see man test), which just like other commands, takes its arguments separated by space:

wrong:
```
  if[x!= y] then echo hello world fi
```
right:
```
  if [ x != y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
to run a program and put its output into a variable, you need $(...) (preferred in bash, not available in sh) or backticks `command` (supported in bash and sh). (and remember that when assigning a variable, quotes are not needed, but in other cases they are important: command "$(command)")

wrong:
```
  APP_ID=command
```
right:
```
  APP_ID=$(command)
```
add spaces around everything when using "[", and you need a semicolon or newline after the "]". This is because "[" is a bash builtin command, and the non-builtin one is also known as "test" (see man test), which just like other commands, takes its arguments separated by space:

wrong:
```
  if[x!= y] then echo hello world fi
```
right:
```
  if [ x != y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

added backticks literally in there..coudln't figure out the escaping before

Source Link

edited Jul 13, 2016 at 8:45

Peter

1.3k
10
9

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
to run a program and put its output into a variable, you need $(...) (preferred in bash, not available in sh) or backticks `command` (supported in bash and sh). (and remember that when assigning a variable, quotes are not needed, but in other cases they are important: command "$(command)")

wrong:
```
  APP_ID=command
```
right:
```
  APP_ID=$(command)
```

add spaces around everything when using "[", and you need a semicolon or newline after the "]". This is because "[" is a command also known as "test" (see man test), which just like other commands, takes its arguments separated by space:

wrong:
```
  if[x!= y] then echo hello world fi
```
right:
```
  if [ x != y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
add spaces around everything when using "[", and you need a semicolon or newline after the "]". This is because "[" is a command also known as "test" (see man test), which just like other commands, takes its arguments separated by space:

wrong:
```
  if[x!= y] then echo hello world fi
```
right:
```
  if [ x != y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
to run a program and put its output into a variable, you need $(...) (preferred in bash, not available in sh) or backticks `command` (supported in bash and sh). (and remember that when assigning a variable, quotes are not needed, but in other cases they are important: command "$(command)")

wrong:
```
  APP_ID=command
```
right:
```
  APP_ID=$(command)
```

add spaces around everything when using "[", and you need a semicolon or newline after the "]". This is because "[" is a command also known as "test" (see man test), which just like other commands, takes its arguments separated by space:

wrong:
```
  if[x!= y] then echo hello world fi
```
right:
```
  if [ x != y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

added backticks for man test... do I get an award for record number of edits yet?

Source Link

edited Jul 13, 2016 at 8:32

Peter

1.3k
10
9

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
add spaces around everything when using "[", and you need a semicolon or newline after the "]". This is because "[" is a command also known as "test" (see man test), which just like other commands, takes its arguments separated by space:

wrong:
```
  if[x != y] then echo hello world fi
```
right:
```
  if [ x != y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
add spaces around everything when using "[", and you need a semicolon or newline after the "]":

wrong:
```
  if[x = y] then echo hello world fi
```
right:
```
  if [ x = y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

Your syntax has many problems:

remove spaces around "=" when setting a variable

wrong:
```
  APP_ID = value
```
right:
```
  APP_ID=value
```
add spaces around everything when using "[", and you need a semicolon or newline after the "]". This is because "[" is a command also known as "test" (see man test), which just like other commands, takes its arguments separated by space:

wrong:
```
  if[x!= y] then echo hello world fi
```
right:
```
  if [ x != y ]; then echo hello world; fi
```
use double quotes, not single quotes when you want to expand a variable

wrong:
```
  if [ '' != '${APP_ID}' ]; then
```
right:
```
  if [ '' != "${APP_ID}" ]; then
```
Also for the above example, you can use -n (non-empty) instead of comparing to empty string
```
  if [ -n "${APP_ID}" ]; then
```

And for the ps example, you don't need grep and awk:

  APP_ID=$(ps -C whoami --no-header --format 'pid')

And so here is the fixed up script:

APP_ID=$(ps -C whoami --no-header --format 'pid')

if [ -n "${APP_ID}" ]; then
    echo "Stopping instance $APP_ID"
fi

Source Link

answered Jul 13, 2016 at 8:23

Peter

1.3k
10
9

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Your syntax has many problems:

And so here is the fixed up script:

Your syntax has many problems:

And so here is the fixed up script:

Your syntax has many problems:

And so here is the fixed up script:

Your syntax has many problems:

And so here is the fixed up script:

Your syntax has many problems:

And so here is the fixed up script:

Your syntax has many problems:

And so here is the fixed up script:

Your syntax has many problems:

And so here is the fixed up script:

Your syntax has many problems:

And so here is the fixed up script:

Your syntax has many problems:

And so here is the fixed up script: