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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-09-10 11:58:50 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-09-14 12:50:25 -0300 |
| commit | 2d729f6a8ac3edbf68de7239fab96c9736946af5 (patch) | |
| tree | ec0a1ee34c30e969b6affb211850c7e1bcf320d0 /tools/lib | |
| parent | e0838e029f4f6f271d6172b18f5473558ebdea1b (diff) | |
| download | linux-2d729f6a8ac3edbf68de7239fab96c9736946af5.tar.bz2 | |
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.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-4a12m4d5k8m4qgc1vguocvei@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/api/fs/fs.c | 45 | ||||
| -rw-r--r-- | tools/lib/api/fs/fs.h | 4 |
2 files changed, 49 insertions, 0 deletions
diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c index 791509346178..732dbef588b0 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 f654bcb99d1e..d024a7f682f6 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__ */ |