# Pipe Fail: `trypipe`

> Checks for non-zero exits of each function in a pipeline

## Description

`trypipe` checks the state of each function and exits the block if any of them
fail. Where `trypipe` differs from regular `try` blocks is `trypipe` will check
every process along the pipeline as well as the terminating function (which
`try` only validates against). The downside to this is that piped functions can
no longer run in parallel.

## Usage

```
trypipe { code-block } -> <stdout>

<stdin> -> trypipe { -> code-block } -> <stdout>
```

## Examples

```
trypipe {
    out "Hello, World!" -> grep: "non-existent string" -> cat
    out "This command will be ignored"
}
```

Formated pager (`less`) where the pager isn't called if the formatter (`pretty`) fails (eg input isn't valid JSON):

```
func pless {
    -> trypipe { -> pretty -> less }
}
```

## Detail

A failure is determined by:

* Any process that returns a non-zero exit number

You can see which run mode your functions are executing under via the `fid-list`
command.

## See Also

* [Caught Error Block: `catch`](../commands/catch.md):
  Handles the exception code raised by `try` or `trypipe`
* [Disable Error Handling In Block: `unsafe`](../commands/unsafe.md):
  Execute a block of code, always returning a zero exit number
* [Display Running Functions: `fid-list`](../commands/fid-list.md):
  Lists all running functions within the current Murex session
* [Function / Module Defaults: `runmode`](../commands/runmode.md):
  Alter the scheduler's behaviour at higher scoping level
* [If Conditional: `if`](../commands/if.md):
  Conditional statement to execute different blocks of code depending on the result of the condition
* [Schedulers](../user-guide/schedulers.md):
  Overview of the different schedulers (or 'run modes') in Murex
* [Stderr Checking In Pipes: `trypipeerr`](../commands/trypipeerr.md):
  Checks state of each function in a pipeline and exits block on error
* [Stderr Checking In TTY: `tryerr`](../commands/tryerr.md):
  Handles errors inside a block of code
* [Switch Conditional: `switch`](../commands/switch.md):
  Blocks of cascading conditionals
* [Try Block: `try`](../commands/try.md):
  Handles non-zero exits inside a block of code

<hr/>

This document was generated from [builtins/core/structs/try_doc.yaml](https://github.com/lmorg/murex/blob/master/builtins/core/structs/try_doc.yaml).