Manpages - sd_path_lookup.3

Table of Contents

NAME

sd_path_lookup, sd_path_lookup_strv - Query well-known file system paths

SYNOPSIS

  #include <systemd/sd-path.h>
  enum {
          SD_PATH_TEMPORARY,
          SD_PATH_TEMPORARY_LARGE,

          SD_PATH_SYSTEM_BINARIES,
          SD_PATH_SYSTEM_INCLUDE,
          SD_PATH_SYSTEM_LIBRARY_PRIVATE,
          SD_PATH_SYSTEM_LIBRARY_ARCH,
          SD_PATH_SYSTEM_SHARED,
          SD_PATH_SYSTEM_CONFIGURATION_FACTORY,
          SD_PATH_SYSTEM_STATE_FACTORY,

          SD_PATH_SYSTEM_CONFIGURATION,
          SD_PATH_SYSTEM_RUNTIME,
          SD_PATH_SYSTEM_RUNTIME_LOGS,
          SD_PATH_SYSTEM_STATE_PRIVATE,
          SD_PATH_SYSTEM_STATE_LOGS,
          SD_PATH_SYSTEM_STATE_CACHE,
          SD_PATH_SYSTEM_STATE_SPOOL,

          SD_PATH_USER_BINARIES,
          SD_PATH_USER_LIBRARY_PRIVATE,
          SD_PATH_USER_LIBRARY_ARCH,
          SD_PATH_USER_SHARED,

          SD_PATH_USER_CONFIGURATION,
          SD_PATH_USER_RUNTIME,
          SD_PATH_USER_STATE_CACHE,

          SD_PATH_USER,
          SD_PATH_USER_DOCUMENTS,
          SD_PATH_USER_MUSIC,
          SD_PATH_USER_PICTURES,
          SD_PATH_USER_VIDEOS,
          SD_PATH_USER_DOWNLOAD,
          SD_PATH_USER_PUBLIC,
          SD_PATH_USER_TEMPLATES,
          SD_PATH_USER_DESKTOP,

          SD_PATH_SEARCH_BINARIES,
          SD_PATH_SEARCH_BINARIES_DEFAULT,
          SD_PATH_SEARCH_LIBRARY_PRIVATE,
          SD_PATH_SEARCH_LIBRARY_ARCH,
          SD_PATH_SEARCH_SHARED,
          SD_PATH_SEARCH_CONFIGURATION_FACTORY,
          SD_PATH_SEARCH_STATE_FACTORY,
          SD_PATH_SEARCH_CONFIGURATION,

          SD_PATH_SYSTEMD_UTIL,
          SD_PATH_SYSTEMD_SYSTEM_UNIT,
          SD_PATH_SYSTEMD_SYSTEM_PRESET,
          SD_PATH_SYSTEMD_USER_UNIT,
          SD_PATH_SYSTEMD_USER_PRESET,
          SD_PATH_SYSTEMD_SYSTEM_CONF,
          SD_PATH_SYSTEMD_USER_CONF,
          SD_PATH_SYSTEMD_SEARCH_SYSTEM_UNIT,
          SD_PATH_SYSTEMD_SEARCH_USER_UNIT,
          SD_PATH_SYSTEMD_SYSTEM_GENERATOR,
          SD_PATH_SYSTEMD_USER_GENERATOR,
          SD_PATH_SYSTEMD_SEARCH_SYSTEM_GENERATOR,
          SD_PATH_SYSTEMD_SEARCH_USER_GENERATOR,
          SD_PATH_SYSTEMD_SLEEP,
          SD_PATH_SYSTEMD_SHUTDOWN,

          SD_PATH_TMPFILES,
          SD_PATH_SYSUSERS,
          SD_PATH_SYSCTL,
          SD_PATH_BINFMT,
          SD_PATH_MODULES_LOAD,
          SD_PATH_CATALOG,

          SD_PATH_SYSTEMD_SEARCH_NETWORK,
  };

int sd_path_lookup(uint64_t */type/, const char */suffix/, char **/paths/);*

int sd_path_lookup_strv(uint64_t */type/, const char */suffix/, char ***/paths/);*

DESCRIPTION

sd_path_lookup() and sd_bus_path_lookup_strv() return a single path or set of file system paths specified by the argument type. In case of sd_path_lookup() a single NUL-terminated string is returned. When type specifies a set of paths, they are concatenated using “:” as a separator (as is traditionally done for e.g. $PATH or $LD_LIBRARY_PATH). In case of sd_path_lookup_strv() a NULL-terminated array of strings is returned (strv). If suffix suffix is given, it is concatenated to each of the paths after a slash (“/”). All returned paths are absolute.

For paths which refer to user directories, the relevant XDG standard is followed, with support for environment variables like $XDG_DOCUMENTS_DIR, $XDG_DESKTOP_DIR, …, and explicit configuration in /etc/xdg/user-dirs.conf or ${XDG_CONFIG_HOME}/user-dirs.dirs. See XDG Base Directory Specification[1] for details.

systemd-path*(1) is a wrapper around *sd_path_lookup() and allows the same set of paths to be queried.

RETURN VALUE

On success, sd_path_lookup() and sd_path_lookup_strv() return a non-negative integer. On failure, a negative errno-style error number is returned by either function.

The returned string or string array (strv) must be *free*(3)d by the caller.

Errors

Returned errors may indicate the following problems:

-EOPNOTSUPP

Unknown identifier type.

-EINVAL

Output argument is NULL.

-ENXIO

Query failed because of an undefined environment variable (e.g. for SD_PATH_USER_RUNTIME when $XDG_RUNTIME_DIR is not defined).

-ENOMEM

Memory allocation failed.

EXAMPLES

Look up the location of ~/Documents

    #include <stdio.h>
    #include <stdlib.h>
    #include <sd-path.h>

    int main(void) {
      int r;
      char *t;

      r = sd_path_lookup(SD_PATH_USER_DOCUMENTS, NULL, &t);
      if (r < 0)
        return EXIT_FAILURE;

      printf("~/Documents: %s\n", t);
      free(t);

      return EXIT_SUCCESS;
    }

Note that the default answer of $HOME/Documents may be overridden by user-dirs.conf or $XDG_DOCUMENTS_DIR.

NOTES

These APIs are implemented as a shared library, which can be compiled and linked to with the libsystemd *pkg-config*(1) file.

SEE ALSO

*systemd-path*(1)

NOTES

Author: dt

Created: 2022-02-20 Sun 20:26