Commit-ID: 2d729f6a8ac3edbf68de7239fab96c9736946af5
Gitweb: http://git.kernel.org/tip/2d729f6a8ac3edbf68de7239fab96c9736946af5
Author: Arnaldo Carvalho de Melo <a...@redhat.com>
AuthorDate: Thu, 10 Sep 2015 11:58:50 -0300
Committer: Arnaldo Carvalho de Melo <a...@redhat.com>
CommitDate: Mon, 14 Sep 2015 12:50:25 -0300
tools lib api fs: Introduce sysfs__read_{int,ull}()
To read either an int or an unsigned long long value from the given
file.
E.g.:
$ cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
3200000
$ ./sysfs__read_ull
devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq=3200000
$
Cc: Adrian Hunter <adrian.hun...@intel.com>
Cc: Borislav Petkov <b...@suse.de>
Cc: David Ahern <dsah...@gmail.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Kan Liang <kan.li...@intel.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Stephane Eranian <eran...@google.com>
Cc: Wang Nan <wangn...@huawei.com>
Link: http://lkml.kernel.org/n/tip-4a12m4d5k8m4qgc1vguoc...@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/lib/api/fs/fs.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
tools/lib/api/fs/fs.h | 4 ++++
2 files changed, 49 insertions(+)
diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index 7915093..732dbef5 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -1,5 +1,6 @@
#include <ctype.h>
#include <errno.h>
+#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
@@ -281,6 +282,50 @@ int filename__read_int(const char *filename, int *value)
return err;
}
+int filename__read_ull(const char *filename, unsigned long long *value)
+{
+ char line[64];
+ int fd = open(filename, O_RDONLY), err = -1;
+
+ if (fd < 0)
+ return -1;
+
+ if (read(fd, line, sizeof(line)) > 0) {
+ *value = strtoull(line, NULL, 10);
+ if (*value != ULLONG_MAX)
+ err = 0;
+ }
+
+ close(fd);
+ return err;
+}
+
+int sysfs__read_ull(const char *entry, unsigned long long *value)
+{
+ char path[PATH_MAX];
+ const char *sysfs = sysfs__mountpoint();
+
+ if (!sysfs)
+ return -1;
+
+ snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
+
+ return filename__read_ull(path, value);
+}
+
+int sysfs__read_int(const char *entry, int *value)
+{
+ char path[PATH_MAX];
+ const char *sysfs = sysfs__mountpoint();
+
+ if (!sysfs)
+ return -1;
+
+ snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
+
+ return filename__read_int(path, value);
+}
+
int sysctl__read_int(const char *sysctl, int *value)
{
char path[PATH_MAX];
diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h
index f654bcb..d024a7f 100644
--- a/tools/lib/api/fs/fs.h
+++ b/tools/lib/api/fs/fs.h
@@ -25,5 +25,9 @@ FS(tracefs)
int filename__read_int(const char *filename, int *value);
+int filename__read_ull(const char *filename, unsigned long long *value);
+
int sysctl__read_int(const char *sysctl, int *value);
+int sysfs__read_int(const char *entry, int *value);
+int sysfs__read_ull(const char *entry, unsigned long long *value);
#endif /* __API_FS__ */
--
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