bashで関数を終了する方法

スクリプト全体を強制終了せずに条件がtrueの場合に関数を終了するには、関数を呼び出す前に戻ってください。

例

# Start script
Do scripty stuff here
Ok now lets call FUNCT
FUNCT
Here is A to come back to

function FUNCT {
  if [ blah is false ]; then
    exit the function and go up to A
  else
    keep running the function
  fi
}

使用する：

return [n]

から help return

return：return [n]

Return from a shell function.

Causes a function or sourced script to exit with the return value
specified by N.  If N is omitted, the return status is that of the
last command executed within the function or script.

Exit Status:
Returns N, or failure if the shell is not executing a function or script.

return演算子を使用：

function FUNCT {
  if [ blah is false ]; then
    return 1 # or return 0, or even you can omit the argument.
  else
    keep running the function
  fi
}

外部関数からエラーなしでexiting せずに戻りたい場合は、次のトリックを使用できます。

do-something-complex() {
  # Using `return` here would only return from `fail`, not from `do-something-complex`.
  # Using `exit` would close the entire shell.
  # So we (ab)use a different feature. :)
  fail() { : "${__fail_fast:?$1}"; }

  nested-func() {
      try-this || fail "This didn't work"
      try-that || fail "That didn't work"
  }
  nested-func
}

試してみる：

$ do-something-complex
try-this: command not found
bash: __fail_fast: This didn't work

これには、オプションでこの機能をオフにできるという利点と欠点があります__fail_fast=x do-something-complex。

これにより、最も外側の関数が1を返すことに注意してください。