treewide: Remove trailing whitespace

[sliver-openvswitch.git] / lib / util.c

diff --git a/lib/util.c b/lib/util.c
index 8f1892e..e8f3adb 100644 (file)
--- a/lib/util.c
+++ b/lib/util.c
@@ -21,18 +21,22 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 #include "coverage.h"
+#include "vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(util)
 
 const char *program_name;
 
 void
-out_of_memory(void) 
+out_of_memory(void)
 {
     ovs_fatal(0, "virtual memory exhausted");
 }
 
 void *
-xcalloc(size_t count, size_t size) 
+xcalloc(size_t count, size_t size)
 {
     void *p = count && size ? calloc(count, size) : malloc(1);
     COVERAGE_INC(util_xalloc);
@@ -49,7 +53,7 @@ xzalloc(size_t size)
 }
 
 void *
-xmalloc(size_t size) 
+xmalloc(size_t size)
 {
     void *p = malloc(size ? size : 1);
     COVERAGE_INC(util_xalloc);
@@ -60,7 +64,7 @@ xmalloc(size_t size)
 }
 
 void *
-xrealloc(void *p, size_t size) 
+xrealloc(void *p, size_t size)
 {
     p = realloc(p, size ? size : 1);
     COVERAGE_INC(util_xalloc);
@@ -88,7 +92,7 @@ xmemdup0(const char *p_, size_t length)
 }
 
 char *
-xstrdup(const char *s) 
+xstrdup(const char *s)
 {
     return xmemdup0(s, strlen(s));
 }
@@ -152,7 +156,8 @@ ovs_fatal(int err_no, const char *format, ...)
     vfprintf(stderr, format, args);
     va_end(args);
     if (err_no != 0)
-        fprintf(stderr, " (%s)", strerror(err_no));
+        fprintf(stderr, " (%s)",
+                err_no == EOF ? "end of file" : strerror(err_no));
     putc('\n', stderr);
 
     exit(EXIT_FAILURE);
@@ -187,7 +192,7 @@ void set_program_name(const char *argv0)
 
 /* Print the version information for the program.  */
 void
-ovs_print_version(char *date, char *time, 
+ovs_print_version(char *date, char *time,
                   uint8_t min_ofp, uint8_t max_ofp)
 {
     printf("%s (Open vSwitch) "VERSION BUILDNR"\n", program_name);
@@ -358,6 +363,37 @@ hexit_value(int c)
     NOT_REACHED();
 }
 
+/* Returns the current working directory as a malloc()'d string, or a null
+ * pointer if the current working directory cannot be determined. */
+char *
+get_cwd(void)
+{
+    long int path_max;
+    size_t size;
+
+    /* Get maximum path length or at least a reasonable estimate. */
+    path_max = pathconf(".", _PC_PATH_MAX);
+    size = (path_max < 0 ? 1024
+            : path_max > 10240 ? 10240
+            : path_max);
+
+    /* Get current working directory. */
+    for (;;) {
+        char *buf = xmalloc(size);
+        if (getcwd(buf, size)) {
+            return xrealloc(buf, strlen(buf) + 1);
+        } else {
+            int error = errno;
+            free(buf);
+            if (error != ERANGE) {
+                VLOG_WARN("getcwd failed (%s)", strerror(error));
+                return NULL;
+            }
+            size *= 2;
+        }
+    }
+}
+
 /* Returns the directory name portion of 'file_name' as a malloc()'d string,
  * similar to the POSIX dirname() function but thread-safe. */
 char *
@@ -384,8 +420,35 @@ dir_name(const char *file_name)
     }
 }
 
+/* If 'file_name' starts with '/', returns a copy of 'file_name'.  Otherwise,
+ * returns an absolute path to 'file_name' considering it relative to 'dir',
+ * which itself must be absolute.  'dir' may be null or the empty string, in
+ * which case the current working directory is used.
+ *
+ * Returns a null pointer if 'dir' is null and getcwd() fails. */
+char *
+abs_file_name(const char *dir, const char *file_name)
+{
+    if (file_name[0] == '/') {
+        return xstrdup(file_name);
+    } else if (dir && dir[0]) {
+        char *separator = dir[strlen(dir) - 1] == '/' ? "" : "/";
+        return xasprintf("%s%s%s", dir, separator, file_name);
+    } else {
+        char *cwd = get_cwd();
+        if (cwd) {
+            char *abs_name = xasprintf("%s/%s", cwd, file_name);
+            free(cwd);
+            return abs_name;
+        } else {
+            return NULL;
+        }
+    }
+}
+
+
 /* Pass a value to this function if it is marked with
- * __attribute__((warn_unused_result)) and you genuinely want to ignore 
- * its return value.  (Note that every scalar type can be implicitly 
+ * __attribute__((warn_unused_result)) and you genuinely want to ignore
+ * its return value.  (Note that every scalar type can be implicitly
  * converted to bool.) */
 void ignore(bool x OVS_UNUSED) { }