91c8ceec2c
With thanks to @LaryBattle for the discussion in #46 and @kilaka for the discussion in #344. Fixes #46 Closes #344
42 lines
1.2 KiB
Go
42 lines
1.2 KiB
Go
// Go makes it possible to _recover_ from a panic, by
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// using the `recover` built-in function. A `recover` can
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// stop a `panic` from aborting the program and let it
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// continue with execution instead.
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// An example of where this can be useful: a server
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// wouldn't want to crash if one of the client connections
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// exhibits a critical error. Instead, the server would
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// want to close that connection and continue serving
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// other clients. In fact, this is what Go's `net/http`
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// does by default for HTTP servers.
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package main
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import "fmt"
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// This function panics.
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func mayPanic() {
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panic("a problem")
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}
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func main() {
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// `recover` must be called within a deferred function.
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// When the enclosing function panics, the defer will
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// activate and a `recover` call within it will catch
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// the panic.
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defer func() {
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if r := recover(); r != nil {
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// The return value of `recover` is the error raised in
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// the call to `panic`.
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fmt.Println("Recovered. Error:\n", r)
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}
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}()
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mayPanic()
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// This code will not run, because `mayPanic` panics.
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// The execution of `main` stops at the point of the
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// panic and resumes in the deferred closure.
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fmt.Println("After mayPanic()")
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}
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