[libvirt] [PATCH v2 1/3] util: command: Introduce virCommandAddEnvXDG helper

[Erik Skultety]

Some modules/libraries within QEMU could make use of the XDG_ vars when
writing their data to the disk. Define the most common XDG variables
and point them to the specific driver's libDir, i.e.

XDG_CACHE_HOME -> /var/lib/libvirt/<driver>/.cache
XDG_DATA_HOME -> /var/lib/libvirt/<driver>/.local/share
XDG_CONFIG_HOME -> /var/lib/libvirt/<driver>/.config

Signed-off-by: Erik Skultety <eskultet at redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/util/vircommand.c    | 21 +++++++++++++++++++++
 src/util/vircommand.h    |  2 ++
 3 files changed, 24 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index d2a240fc7a..92e21d3939 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1628,6 +1628,7 @@ virCommandAddEnvPassAllowSUID;
 virCommandAddEnvPassBlockSUID;
 virCommandAddEnvPassCommon;
 virCommandAddEnvString;
+virCommandAddEnvXDG;
 virCommandAllowCap;
 virCommandClearCaps;
 virCommandDaemonize;
diff --git a/src/util/vircommand.c b/src/util/vircommand.c
index 84a65a2f6d..15e2f0ef1e 100644
--- a/src/util/vircommand.c
+++ b/src/util/vircommand.c
@@ -1483,6 +1483,27 @@ virCommandAddEnvPassCommon(virCommandPtr cmd)
     virCommandAddEnvPassBlockSUID(cmd, "TMPDIR", NULL);
 }
 
+
+void
+virCommandAddEnvXDG(virCommandPtr cmd, const char *baseDir)
+{
+    if (!cmd || cmd->has_error)
+        return;
+
+    if (VIR_RESIZE_N(cmd->env, cmd->maxenv, cmd->nenv, 3) < 0) {
+        cmd->has_error = ENOMEM;
+        return;
+    }
+
+    virCommandAddEnvFormat(cmd, "XDG_DATA_HOME=%s/%s",
+                           baseDir, ".local/share");
+    virCommandAddEnvFormat(cmd, "XDG_CACHE_HOME=%s/%s",
+                           baseDir, ".cache");
+    virCommandAddEnvFormat(cmd, "XDG_CONFIG_HOME=%s/%s",
+                           baseDir, ".config");
+}
+
+
 /**
  * virCommandAddArg:
  * @cmd: the command to modify
diff --git a/src/util/vircommand.h b/src/util/vircommand.h
index 99849051f8..efdc5dd00d 100644
--- a/src/util/vircommand.h
+++ b/src/util/vircommand.h
@@ -122,6 +122,8 @@ void virCommandAddEnvPassAllowSUID(virCommandPtr cmd,
 
 void virCommandAddEnvPassCommon(virCommandPtr cmd);
 
+void virCommandAddEnvXDG(virCommandPtr cmd, const char *baseDir);
+
 void virCommandAddArg(virCommandPtr cmd,
                       const char *val) ATTRIBUTE_NONNULL(2);
 
-- 
2.20.1