Re: [PATCH v2 1/4] tools: iio: Move printf failure messages to stderr

[Julia Lawall <julia.lawall@lip6.fr>]

> Yes, I could have included all in a single patch, but I tried to
> automatize this task and build a rather generic semantic patch in
> coccinelle for the substitutions. Had I included all in one patch, the
> changes with coccinelle wouldn't have been differentiated from the
> other ones. If that is okay, I think I can merge them in one patch.

If it seems important, then you can say in the commit message what was done
by hand.

julia


> >> Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
> >> ---
> >> Changes in v2:
> >>  - s/failiure/failure
> >>
> >>  tools/iio/generic_buffer.c    | 17 ++++++++++-------
> >>  tools/iio/iio_event_monitor.c |  6 +++---
> >>  tools/iio/iio_utils.c         | 34 ++++++++++++++++++++--------------
> >>  3 files changed, 33 insertions(+), 24 deletions(-)
> >>
> >> diff --git a/tools/iio/generic_buffer.c b/tools/iio/generic_buffer.c
> >> index 0e73723..2f4e12f 100644
> >> --- a/tools/iio/generic_buffer.c
> >> +++ b/tools/iio/generic_buffer.c
> >> @@ -271,7 +271,7 @@ int main(int argc, char **argv)
> >>       }
> >>
> >>       if (device_name == NULL) {
> >> -             printf("Device name not set\n");
> >> +             fprintf(stderr, "Device name not set\n");
> >>               print_usage();
> >>               return -1;
> >>       }
> >> @@ -279,7 +279,7 @@ int main(int argc, char **argv)
> >>       /* Find the device requested */
> >>       dev_num = find_type_by_name(device_name, "iio:device");
> >>       if (dev_num < 0) {
> >> -             printf("Failed to find the %s\n", device_name);
> >> +             fprintf(stderr, "Failed to find the %s\n", device_name);
> >>               return dev_num;
> >>       }
> >>
> >> @@ -307,7 +307,8 @@ int main(int argc, char **argv)
> >>               /* Verify the trigger exists */
> >>               trig_num = find_type_by_name(trigger_name, "trigger");
> >>               if (trig_num < 0) {
> >> -                     printf("Failed to find the trigger %s\n", trigger_name);
> >> +                     fprintf(stderr, "Failed to find the trigger %s\n",
> >> +                             trigger_name);
> >>                       ret = trig_num;
> >>                       goto error_free_triggername;
> >>               }
> >> @@ -323,7 +324,7 @@ int main(int argc, char **argv)
> >>        */
> >>       ret = build_channel_array(dev_dir_name, &channels, &num_channels);
> >>       if (ret) {
> >> -             printf("Problem reading scan element information\n");
> >> +             fprintf(stderr, "Problem reading scan element information\n");
> >>               printf("diag %s\n", dev_dir_name);
> >
> > My preference would even be to print it all in just one fprintf.
>
> I thought so, also, but the string would go beyond 80 characters and
> would have to be split which is ugly and brings a warning on it.
>
> >>               goto error_free_triggername;
> >>       }
> >> @@ -350,7 +351,8 @@ int main(int argc, char **argv)
> >>                                                   dev_dir_name,
> >>                                                   trigger_name);
> >>               if (ret < 0) {
> >> -                     printf("Failed to write current_trigger file\n");
> >> +                     fprintf(stderr,
> >> +                             "Failed to write current_trigger file\n");
> >>                       goto error_free_buf_dir_name;
> >>               }
> >>       }
> >> @@ -382,7 +384,7 @@ int main(int argc, char **argv)
> >>       fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
> >>       if (fp == -1) { /* TODO: If it isn't there make the node */
> >>               ret = -errno;
> >> -             printf("Failed to open %s\n", buffer_access);
> >> +             fprintf(stderr, "Failed to open %s\n", buffer_access);
> >>               goto error_free_buffer_access;
> >>       }
> >>
> >
> > At line 410 we have a block:
> >                 read_size = read(fp, data, toread * scan_size);
> >                 if (read_size < 0) {
> >                         if (errno == EAGAIN) {
> >                                 printf("nothing available\n");
> >                                 continue;
> >
> > I'm tempted to say,that this should go to stderr, as well. Any opinions?
>
> I see it more as an informing note, since the device continues looping
> for data, but it could be considered an error as well.
>
> >> @@ -431,7 +433,8 @@ int main(int argc, char **argv)
> >>               ret = write_sysfs_string("trigger/current_trigger",
> >>                                        dev_dir_name, "NULL");
> >>               if (ret < 0)
> >> -                     printf("Failed to write to %s\n", dev_dir_name);
> >> +                     fprintf(stderr, "Failed to write to %s\n",
> >> +                             dev_dir_name);
> >>
> >>  error_close_buffer_access:
> >>       if (close(fp) == -1)
> >> diff --git a/tools/iio/iio_event_monitor.c b/tools/iio/iio_event_monitor.c
> >> index 703f4cb..843bc4c 100644
> >> --- a/tools/iio/iio_event_monitor.c
> >> +++ b/tools/iio/iio_event_monitor.c
> >
> > At line 217:
> >         if (!event_is_known(event)) {
> >                 printf("Unknown event: time: %lld, id: %llx\n",
> >                        event->timestamp, event->id);
> >
> >                 return;
> > Better have this on stderr, as well?
>
> This is more suitable for stderr, indeed.
>
> >> @@ -278,14 +278,14 @@ int main(int argc, char **argv)
> >>       fd = open(chrdev_name, 0);
> >>       if (fd == -1) {
> >>               ret = -errno;
> >> -             fprintf(stdout, "Failed to open %s\n", chrdev_name);
> >> +             fprintf(stderr, "Failed to open %s\n", chrdev_name);
> >>               goto error_free_chrdev_name;
> >>       }
> >>
> >>       ret = ioctl(fd, IIO_GET_EVENT_FD_IOCTL, &event_fd);
> >>       if (ret == -1 || event_fd == -1) {
> >>               ret = -errno;
> >> -             fprintf(stdout, "Failed to retrieve event fd\n");
> >> +             fprintf(stderr, "Failed to retrieve event fd\n");
> >>               if (close(fd) == -1)
> >>                       perror("Failed to close character device file");
> >>
> >
> > A similar borderline case as above in line 301:
> >                 ret = read(event_fd, &event, sizeof(event));
> >                 if (ret == -1) {
> >                         if (errno == EAGAIN) {
> >                                 printf("nothing available\n");
> >                                 continue;
> >
> >> @@ -311,7 +311,7 @@ int main(int argc, char **argv)
> >>               }
> >>
> >>               if (ret != sizeof(event)) {
> >> -                     printf("Reading event failed!\n");
> >> +                     fprintf(stderr, "Reading event failed!\n");
> >>                       ret = -EIO;
> >>                       break;
> >>               }
> >> diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c
> >> index 8fb3214..46dfa3f 100644
> >> --- a/tools/iio/iio_utils.c
> >> +++ b/tools/iio/iio_utils.c
> >> @@ -140,7 +140,8 @@ int iioutils_get_type(unsigned *is_signed, unsigned *bytes, unsigned *bits_used,
> >>                       sysfsfp = fopen(filename, "r");
> >>                       if (sysfsfp == NULL) {
> >>                               ret = -errno;
> >> -                             printf("failed to open %s\n", filename);
> >> +                             fprintf(stderr, "failed to open %s\n",
> >> +                                     filename);
> >>                               goto error_free_filename;
> >>                       }
> >>
> >> @@ -152,7 +153,8 @@ int iioutils_get_type(unsigned *is_signed, unsigned *bytes, unsigned *bits_used,
> >>                                    &padint, shift);
> >>                       if (ret < 0) {
> >>                               ret = -errno;
> >> -                             printf("failed to pass scan type description\n");
> >> +                             fprintf(stderr,
> >> +                                     "failed to pass scan type description\n");
> >>                               goto error_close_sysfsfp;
> >>                       } else if (ret != 5) {
> >>                               ret = -EIO;
> >> @@ -170,7 +172,8 @@ int iioutils_get_type(unsigned *is_signed, unsigned *bytes, unsigned *bits_used,
> >>                       *is_signed = (signchar == 's');
> >>                       if (fclose(sysfsfp)) {
> >>                               ret = -errno;
> >> -                             printf("Failed to close %s\n", filename);
> >> +                             fprintf(stderr, "Failed to close %s\n",
> >> +                                     filename);
> >>                               goto error_free_filename;
> >>                       }
> >>
> >> @@ -454,7 +457,8 @@ int build_channel_array(const char *device_dir,
> >>                       sysfsfp = fopen(filename, "r");
> >>                       if (sysfsfp == NULL) {
> >>                               ret = -errno;
> >> -                             printf("failed to open %s\n", filename);
> >> +                             fprintf(stderr, "failed to open %s\n",
> >> +                                     filename);
> >>                               free(filename);
> >>                               goto error_cleanup_array;
> >>                       }
> >> @@ -581,11 +585,13 @@ int find_type_by_name(const char *name, const char *type)
> >>                       ret = sscanf(ent->d_name + strlen(type), "%d", &number);
> >>                       if (ret < 0) {
> >>                               ret = -errno;
> >> -                             printf("failed to read element number\n");
> >> +                             fprintf(stderr,
> >> +                                     "failed to read element number\n");
> >>                               goto error_close_dir;
> >>                       } else if (ret != 1) {
> >>                               ret = -EIO;
> >> -                             printf("failed to match element number\n");
> >> +                             fprintf(stderr,
> >> +                                     "failed to match element number\n");
> >>                               goto error_close_dir;
> >>                       }
> >>
> >> @@ -664,7 +670,7 @@ static int _write_sysfs_int(const char *filename, const char *basedir, int val,
> >>       sysfsfp = fopen(temp, "w");
> >>       if (sysfsfp == NULL) {
> >>               ret = -errno;
> >> -             printf("failed to open %s\n", temp);
> >> +             fprintf(stderr, "failed to open %s\n", temp);
> >>               goto error_free;
> >>       }
> >>
> >> @@ -685,7 +691,7 @@ static int _write_sysfs_int(const char *filename, const char *basedir, int val,
> >>               sysfsfp = fopen(temp, "r");
> >>               if (sysfsfp == NULL) {
> >>                       ret = -errno;
> >> -                     printf("failed to open %s\n", temp);
> >> +                     fprintf(stderr, "failed to open %s\n", temp);
> >>                       goto error_free;
> >>               }
> >>
> >> @@ -750,7 +756,7 @@ static int _write_sysfs_string(const char *filename, const char *basedir,
> >>       char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
> >>
> >>       if (temp == NULL) {
> >> -             printf("Memory allocation failed\n");
> >> +             fprintf(stderr, "Memory allocation failed\n");
> >>               return -ENOMEM;
> >>       }
> >>
> >> @@ -761,7 +767,7 @@ static int _write_sysfs_string(const char *filename, const char *basedir,
> >>       sysfsfp = fopen(temp, "w");
> >>       if (sysfsfp == NULL) {
> >>               ret = -errno;
> >> -             printf("Could not open %s\n", temp);
> >> +             fprintf(stderr, "Could not open %s\n", temp);
> >>               goto error_free;
> >>       }
> >>
> >> @@ -782,7 +788,7 @@ static int _write_sysfs_string(const char *filename, const char *basedir,
> >>               sysfsfp = fopen(temp, "r");
> >>               if (sysfsfp == NULL) {
> >>                       ret = -errno;
> >> -                     printf("Could not open file to verify\n");
> >> +                     fprintf(stderr, "Could not open file to verify\n");
> >>                       goto error_free;
> >>               }
> >>
> >> @@ -856,7 +862,7 @@ int read_sysfs_posint(const char *filename, const char *basedir)
> >>       char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
> >>
> >>       if (temp == NULL) {
> >> -             printf("Memory allocation failed");
> >> +             fprintf(stderr, "Memory allocation failed");
> >>               return -ENOMEM;
> >>       }
> >>
> >> @@ -903,7 +909,7 @@ int read_sysfs_float(const char *filename, const char *basedir, float *val)
> >>       char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
> >>
> >>       if (temp == NULL) {
> >> -             printf("Memory allocation failed");
> >> +             fprintf(stderr, "Memory allocation failed");
> >>               return -ENOMEM;
> >>       }
> >>
> >> @@ -950,7 +956,7 @@ int read_sysfs_string(const char *filename, const char *basedir, char *str)
> >>       char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
> >>
> >>       if (temp == NULL) {
> >> -             printf("Memory allocation failed");
> >> +             fprintf(stderr, "Memory allocation failed");
> >>               return -ENOMEM;
> >>       }
> >>
> >>
> >
>