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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | HISTORY | SEE ALSO | COLOPHON |
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SD_JSON...ET_FIELD(3) sd_json_variant_unset_field SD_JSON...ET_FIELD(3)
sd_json_variant_unset_field - Remove a specific field from a JSON
object
#include <systemd/sd-json.h>
int sd_json_variant_unset_field(sd_json_variant **object,
const char *field);
sd_json_variant_unset_field() takes a pointer to a pointer to a
JSON object and a field name. If the object contains a field under
the specified name, a new JSON object is allocated that is a copy
of the original one, however the specified field is removed. The
object parameter is updated to point to the new object, which has
an initial reference counter of one. The reference counter of the
original object is decremented by one. Or in other words: the
specified object is replaced by one with the field removed.
If the referenced object does not contain a field matching the
specified name, no operation is executed.
Similar, if a NULL pointer is referenced, no operation is
executed.
On success, and if a field was removed
sd_json_variant_unset_field() returns a positive non-zero integer.
If no matching field was found it returns zero. On failure, it
returns a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
An argument is invalid.
-ENOMEM
Memory allocation failed.
Functions described here are available as a shared library, which
can be compiled against and linked to with the
libsystemd pkg-config(1) file.
The code described here uses getenv(3), which is declared to be
not multi-thread-safe. This means that the code calling the
functions described here must not call setenv(3) from a parallel
thread. It is recommended to only do calls to setenv() from an
early phase of the program when no other threads have been
started.
sd_json_variant_unset_field() was added in version 258.
systemd(1), sd-json(3)
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a
bug report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2025-02-02. (At that
time, the date of the most recent commit that was found in the
repository was 2025-02-02.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
systemd 258~devel SD_JSON...ET_FIELD(3)
Pages that refer to this page: systemd.directives(7), systemd.index(7)
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HTML rendering created 2025-02-02 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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