text-based mount command: add function to parse numeric mount options

[nfs-utils.git] / utils / mount / parse_opt.c

diff --git a/utils/mount/parse_opt.c b/utils/mount/parse_opt.c
index cb398bd2d4d714fd5aa1ab798f3763ed0e9a80f4..f61d0dd6470da10448d7cc3d9df3f0762667c405 100644 (file)
--- a/utils/mount/parse_opt.c
+++ b/utils/mount/parse_opt.c
@@ -36,6 +36,10 @@
  */
 
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <ctype.h>
 #include <unistd.h>
 #include <stdio.h>
@@ -365,6 +369,57 @@ char *po_get(struct mount_options *options, char *keyword)
        return NULL;
 }
 
+/**
+ * po_get_numeric - return numeric value of rightmost instance of keyword option
+ * @options: pointer to mount options
+ * @keyword: pointer to a C string containing option keyword for which to search
+ * @value: OUT: set to the value of the keyword
+ *
+ * This is specifically for parsing keyword options that take only a numeric
+ * value.  If multiple instances of the same option are present in a mount
+ * option list, the rightmost instance is always the effective one.
+ *
+ * Returns:
+ *     * PO_FOUND if the keyword was found and the value is numeric; @value is
+ *       set to the keyword's value
+ *     * PO_NOT_FOUND if the keyword was not found
+ *     * PO_BAD_VALUE if the keyword was found, but the value is not numeric
+ *
+ * These last two are separate in case the caller wants to warn about bad mount
+ * options instead of silently using a default.
+ */
+#ifdef HAVE_STRTOL
+po_found_t po_get_numeric(struct mount_options *options, char *keyword, long *value)
+{
+       char *option, *endptr;
+       long tmp;
+
+       option = po_get(options, keyword);
+       if (option == NULL)
+               return PO_NOT_FOUND;
+
+       errno = 0;
+       tmp = strtol(option, &endptr, 10);
+       if (errno == 0 && endptr != option) {
+               *value = tmp;
+               return PO_FOUND;
+       }
+       return PO_BAD_VALUE;
+}
+#else  /* HAVE_STRTOL */
+po_found_t po_get_numeric(struct mount_options *options, char *keyword, long *value)
+{
+       char *option;
+
+       option = po_get(options, keyword);
+       if (option == NULL)
+               return PO_NOT_FOUND;
+
+       *value = atoi(option);
+       return PO_FOUND;
+}
+#endif /* HAVE_STRTOL */
+
 /**
  * po_rightmost - determine the relative position of two options
  * @options: pointer to mount options