[PATCH] app/test: simplify getting the current file prefix

[Bruce Richardson <bruce.richardson@intel.com>]

Rather than opening particular fd's in the /proc directory, just use the
rte_eal_get_runtime_dir() function to derive the file-prefix in use.
Since the runtime dir call cannot return NULL, we can simplify/remove
the error handling where it's used.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 app/test/process.h | 23 ++++-------------------
 1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/app/test/process.h b/app/test/process.h
index 402dc4f96f..1ab5671943 100644
--- a/app/test/process.h
+++ b/app/test/process.h
@@ -8,12 +8,11 @@
 #include <errno.h>  /* errno */
 #include <limits.h> /* PATH_MAX */
 #ifndef RTE_EXEC_ENV_WINDOWS
-#include <libgen.h> /* basename et al */
 #include <sys/wait.h>
 #endif
 #include <stdlib.h> /* NULL */
 #include <string.h> /* strerror */
-#include <unistd.h> /* readlink */
+#include <unistd.h>
 #include <dirent.h>
 
 #include <rte_string_fns.h> /* strlcpy */
@@ -239,17 +238,7 @@ file_prefix_arg(void)
 static inline char *
 get_current_prefix(char *prefix, int size)
 {
-	char buf[PATH_MAX];
-
-	/* get file for config (fd is always 3) return NULL on error */
-	if (readlink("/proc/self/fd/3", buf, sizeof(buf)) == -1)
-		return NULL;
-
-	/*
-	 * path should be something like "/var/run/dpdk/config"
-	 * which results in prefix of "dpdk"
-	 */
-	rte_basename(dirname(buf), prefix, size);
+	rte_basename(rte_eal_get_runtime_dir(), prefix, size);
 	return prefix;
 }
 
@@ -260,12 +249,8 @@ file_prefix_arg(void)
 	static char prefix[NAME_MAX + sizeof("--file-prefix=")];
 	char tmp[NAME_MAX];
 
-	if (get_current_prefix(tmp, sizeof(tmp)) == NULL) {
-		fprintf(stderr, "Error - unable to get current prefix!\n");
-		return NULL;
-	}
-
-	snprintf(prefix, sizeof(prefix), "--file-prefix=%s", tmp);
+	snprintf(prefix, sizeof(prefix), "--file-prefix=%s",
+			get_current_prefix(tmp, sizeof(tmp)));
 	return prefix;
 #endif
 }
-- 
2.51.0