perf probe: Add argv_split() from lib/argv_split.c

Add argv_split() ported from lib/argv_split.c to string.c and
use it in util/probe-event.c.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091201002005.10235.55602.stgit@harusame>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 101 insertions, 0 deletions

diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
index 227043577e06..0977cf431789 100644
--- a/tools/perf/util/string.c
+++ b/tools/perf/util/string.c
@@ -127,3 +127,104 @@ out_err:
 out:
         return length;
 }
+
+/*
+ * Helper function for splitting a string into an argv-like array.
+ * originaly copied from lib/argv_split.c
+ */
+static const char *skip_sep(const char *cp)
+{
+        while (*cp && isspace(*cp))
+                cp++;
+
+        return cp;
+}
+
+static const char *skip_arg(const char *cp)
+{
+        while (*cp && !isspace(*cp))
+                cp++;
+
+        return cp;
+}
+
+static int count_argc(const char *str)
+{
+        int count = 0;
+
+        while (*str) {
+                str = skip_sep(str);
+                if (*str) {
+                        count++;
+                        str = skip_arg(str);
+                }
+        }
+
+        return count;
+}
+
+/**
+ * argv_free - free an argv
+ * @argv - the argument vector to be freed
+ *
+ * Frees an argv and the strings it points to.
+ */
+void argv_free(char **argv)
+{
+        char **p;
+        for (p = argv; *p; p++)
+                free(*p);
+
+        free(argv);
+}
+
+/**
+ * argv_split - split a string at whitespace, returning an argv
+ * @str: the string to be split
+ * @argcp: returned argument count
+ *
+ * Returns an array of pointers to strings which are split out from
+ * @str.  This is performed by strictly splitting on white-space; no
+ * quote processing is performed.  Multiple whitespace characters are
+ * considered to be a single argument separator.  The returned array
+ * is always NULL-terminated.  Returns NULL on memory allocation
+ * failure.
+ */
+char **argv_split(const char *str, int *argcp)
+{
+        int argc = count_argc(str);
+        char **argv = zalloc(sizeof(*argv) * (argc+1));
+        char **argvp;
+
+        if (argv == NULL)
+                goto out;
+
+        if (argcp)
+                *argcp = argc;
+
+        argvp = argv;
+
+        while (*str) {
+                str = skip_sep(str);
+
+                if (*str) {
+                        const char *p = str;
+                        char *t;
+
+                        str = skip_arg(str);
+
+                        t = strndup(p, str-p);
+                        if (t == NULL)
+                                goto fail;
+                        *argvp++ = t;
+                }
+        }
+        *argvp = NULL;
+
+out:
+        return argv;
+
+fail:
+        argv_free(argv);
+        return NULL;
+}