---
name: "psiginfo"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/psignal"
---

# psiginfo(3)

print signal description

Part of [psignal(3)](/psignal/3.md).

## NAME

psignal, psiginfo - print signal description

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <signal.h>
```

**void psignal(int** *sig***, const char \****s***);** **void psiginfo(const siginfo\_t \****pinfo***, const char \****s***);**

Feature Test Macro Requirements for glibc (see [**feature\_test\_macros**(7)](/feature_test_macros/7.md)):

**psignal**():

```
    Since glibc 2.19:
            _DEFAULT_SOURCE
    glibc 2.19 and earlier:
        _BSD_SOURCE || _SVID_SOURCE
```

**psiginfo**():

```
    _POSIX_C_SOURCE >= 200809L
```

## DESCRIPTION

The **psignal**() function displays a message on *stderr* consisting of the string *s*, a colon, a space, a string describing the signal number *sig*, and a trailing newline. If the string *s* is NULL or empty, the colon and space are omitted. If *sig* is invalid, the message displayed will indicate an unknown signal.

The **psiginfo**() function is like **psignal**(), except that it displays information about the signal described by *pinfo*, which should point to a valid *siginfo\_t* structure. As well as the signal description, **psiginfo**() displays information about the origin of the signal, and other information relevant to the signal (e.g., the relevant memory address for hardware-generated signals, the child process ID for **SIGCHLD**, and the user ID and process ID of the sender, for signals set using [**kill**(2)](/kill/2.md) or [**sigqueue**(3)](/sigqueue/3.md)).

## RETURN VALUE

The **psignal**() and **psiginfo**() functions return no value.

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **psignal**(), **psiginfo**() | Thread safety | MT-Safe locale |

## STANDARDS

POSIX.1-2008.

## HISTORY

glibc 2.10. POSIX.1-2008, 4.3BSD.

## BUGS

Up to glibc 2.12, **psiginfo**() had the following bugs:

- •

  In some circumstances, a trailing newline is not printed.

- •

  Additional details are not displayed for real-time signals.

## SEE ALSO

[**sigaction**(2)](/sigaction/2.md), [**perror**(3)](/perror/3.md), [**strsignal**(3)](/strsignal/3.md), [**signal**(7)](/signal/7.md)