---
name: "qb_log_format_set"
section: "3"
platform: "linux"
package: "libqb"
version: "2.0.10-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/qb_log_format_set"
---

# qb\_log\_format\_set(3)

Set the format specifiers.

## NAME

qb\_log\_format\_set - Set the format specifiers.

## SYNOPSIS

```
#include <qb/qblog.h>

void qb_log_format_set(
    int32_t       t,
    const char   *format
);
```

## DESCRIPTION

%n FUNCTION NAME

%f FILENAME

%l FILELINE

%p PRIORITY

%t TIMESTAMP

%T TIMESTAMP with milliseconds

%b BUFFER

%g TAGS

%N name (passed into qb\_log\_init)

%P PID

%H hostname

Any number between % and character specify field length to pad or chop.

## NOTE

Some of the fields are immediately evaluated and remembered for performance reasons, so whenlog messages carry PIDs (not the default) this function needs to be reinvoked following **fork** (**clone**) in the respective children. When already linking with **libpthread**, **pthread\_atfork** callback registration could be useful.

## SEE ALSO

[*qb\_log\_filter\_fn\_set*(3)](/qb_log_filter_fn_set/3.md), *qb\_log\_from\_external\_source\_va2*(3), [*qb\_log\_thread\_start*(3)](/qb_log_thread_start/3.md), [*qb\_log\_target\_user\_data\_get*(3)](/qb_log_target_user_data_get/3.md), [*qb\_log\_tags\_stringify\_fn\_set*(3)](/qb_log_tags_stringify_fn_set/3.md), [*qb\_log\_file\_reopen*(3)](/qb_log_file_reopen/3.md), [*qb\_log\_fini*(3)](/qb_log_fini/3.md), [*qb\_log\_callsites\_dump*(3)](/qb_log_callsites_dump/3.md), [*qb\_log\_ctl2*(3)](/qb_log_ctl2/3.md), [*qb\_log\_target\_user\_data\_set*(3)](/qb_log_target_user_data_set/3.md), [*qb\_log\_target\_format*(3)](/qb_log_target_format/3.md), [*qb\_log\_thread\_priority\_set*(3)](/qb_log_thread_priority_set/3.md), [*qb\_log\_facility2int*(3)](/qb_log_facility2int/3.md), [*qb\_log\_callsites\_register*(3)](/qb_log_callsites_register/3.md), [*qb\_log\_filter\_ctl2*(3)](/qb_log_filter_ctl2/3.md), [*qb\_log\_file\_close*(3)](/qb_log_file_close/3.md), [*qb\_log\_real\_*(3)](/qb_log_real_/3.md), [*qb\_log\_from\_external\_source\_va*(3)](/qb_log_from_external_source_va/3.md), [*qb\_log\_callsite\_get*(3)](/qb_log_callsite_get/3.md), [*qb\_log\_blackbox\_write\_to\_file*(3)](/qb_log_blackbox_write_to_file/3.md), [*qb\_log\_real\_va\_*(3)](/qb_log_real_va_/3.md), [*qb\_log\_from\_external\_source*(3)](/qb_log_from_external_source/3.md), [*qb\_log\_blackbox\_print\_from\_file*(3)](/qb_log_blackbox_print_from_file/3.md), [*qb\_log\_facility2str*(3)](/qb_log_facility2str/3.md), *qb\_log\_callsite\_get2*(3), [*qb\_log\_ctl*(3)](/qb_log_ctl/3.md), [*qb\_log\_filter\_ctl*(3)](/qb_log_filter_ctl/3.md), [*qb\_log\_custom\_close*(3)](/qb_log_custom_close/3.md), [*qb\_log\_init*(3)](/qb_log_init/3.md), [*qb\_log\_file\_open*(3)](/qb_log_file_open/3.md), [*qb\_log\_custom\_open*(3)](/qb_log_custom_open/3.md)

## COPYRIGHT

Copyright (c) 2017 Red Hat, Inc.