:orphan:
# PetscPushErrorHandler
Sets a routine to be called on detection of errors. 
## Synopsis
```
#include "petscsys.h" 
PetscErrorCode PetscPushErrorHandler(PetscErrorCode (*handler)(MPI_Comm comm, int, const char *, const char *, PetscErrorCode, PetscErrorType, const char *, void *), void *ctx)
```
Not Collective


## Input Parameters

- ***handler -*** error handler routine
- ***ctx -*** optional handler context that contains information needed by the handler (for
example file pointers for error messages etc.)



## Calling sequence of `handler`
```none
PetscErrorCode handler(MPI_Comm comm, int line, char *func, char *file, PetscErrorCode n, int p, char *mess, void *ctx);
```

- ***comm -*** communicator over which error occurred
- ***line -*** the line number of the error (indicated by __LINE__)
- ***file -*** the file in which the error was detected (indicated by __FILE__)
- ***n -*** the generic error number (see list defined in include/petscerror.h)
- ***p -*** `PETSC_ERROR_INITIAL` if error just detected, otherwise `PETSC_ERROR_REPEAT`
- ***mess -*** an error text string, usually just printed to the screen
- ***ctx -*** the error handler context



## Options Database Keys

- ***-on_error_attach_debugger <noxterm,gdb or dbx> -*** starts up the debugger if an error occurs
- ***-on_error_abort -*** aborts the program if an error occurs





## Note
The currently available PETSc error handlers include `PetscTraceBackErrorHandler()`,
`PetscAttachDebuggerErrorHandler()`, `PetscAbortErrorHandler()`, and `PetscMPIAbortErrorHandler()`, `PetscReturnErrorHandler()`.


## Fortran Note
You can only push one error handler from Fortran before popping it.


## See Also
 `PetscPopErrorHandler()`, `PetscAttachDebuggerErrorHandler()`, `PetscAbortErrorHandler()`, `PetscTraceBackErrorHandler()`, `PetscPushSignalHandler()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/error/err.c.html#PetscPushErrorHandler">src/sys/error/err.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex27.c.html">src/ksp/ksp/tutorials/ex27.c</A><BR>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/error/err.c)


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