[libvirt] [PATCH 1/3] command: Add virCommandEnvAddFormat

[Cole Robinson]

Similar to virCommandArgAddFormat. We will use this shortly.

Signed-off-by: Cole Robinson <crobinso at redhat.com>
---
 src/libvirt_private.syms |    1 +
 src/util/command.c       |   30 ++++++++++++++++++++++++++++++
 src/util/command.h       |    7 +++++++
 3 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 1b22be6..d89b191 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -99,6 +99,7 @@ virCommandAddArgList;
 virCommandAddArgPair;
 virCommandAddArgSet;
 virCommandAddEnvBuffer;
+virCommandAddEnvFormat;
 virCommandAddEnvPair;
 virCommandAddEnvPass;
 virCommandAddEnvPassCommon;
diff --git a/src/util/command.c b/src/util/command.c
index 862a913..f382cc5 100644
--- a/src/util/command.c
+++ b/src/util/command.c
@@ -259,6 +259,36 @@ virCommandNonblockingFDs(virCommandPtr cmd)
 }
 
 /*
+ * Add an environment variable to the child created by a printf-style format
+ */
+void
+virCommandAddEnvFormat(virCommandPtr cmd, const char *format, ...)
+{
+    char *env;
+    va_list list;
+
+    if (!cmd || cmd->has_error)
+        return;
+
+    va_start(list, format);
+    if (virVasprintf(&env, format, list) < 0) {
+        cmd->has_error = ENOMEM;
+        va_end(list);
+        return;
+    }
+    va_end(list);
+
+    /* Arg plus trailing NULL. */
+    if (VIR_RESIZE_N(cmd->env, cmd->maxenv, cmd->nenv, 1 + 1) < 0) {
+        VIR_FREE(env);
+        cmd->has_error = ENOMEM;
+        return;
+    }
+
+    cmd->env[cmd->nenv++] = env;
+}
+
+/*
  * Add an environment variable to the child
  * using separate name & value strings
  */
diff --git a/src/util/command.h b/src/util/command.h
index ff8ccf5..69e9169 100644
--- a/src/util/command.h
+++ b/src/util/command.h
@@ -98,6 +98,13 @@ void virCommandDaemonize(virCommandPtr cmd);
 void virCommandNonblockingFDs(virCommandPtr cmd);
 
 /*
+ * Add an environment variable to the child created by a printf-style format
+ */
+void
+virCommandAddEnvFormat(virCommandPtr cmd, const char *format, ...)
+                       ATTRIBUTE_NONNULL(2) ATTRIBUTE_FMT_PRINTF(2, 3);
+
+/*
  * Add an environment variable to the child
  * using separate name & value strings
  */
-- 
1.7.4.4