From 096f9b862e605fe08bb30e4f7a381684a8ff82ed Mon Sep 17 00:00:00 2001 From: Hartmut Knaack Date: Sun, 31 May 2015 14:40:00 +0200 Subject: [PATCH] tools:iio:iio_utils: implement digit calculation Previously, the return value of sscanf() was treated as an indication of the digits it would have read. Yet, sscanf() only returns the amount of valid matches. Therefore, introduce a function to calculate the decimal digits of the read number and use this one to commence a colon search, as originally intended. Signed-off-by: Hartmut Knaack Signed-off-by: Jonathan Cameron --- tools/iio/iio_utils.c | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c index c5b4136e648a..60e5ec4165b7 100644 --- a/tools/iio/iio_utils.c +++ b/tools/iio/iio_utils.c @@ -431,6 +431,18 @@ error_ret: return ret; } +int calc_digits(int num) +{ + int count = 0; + + while (num != 0) { + num /= 10; + count++; + } + + return count; +} + /** * find_type_by_name() - function to match top level types by name * @name: top level type instance name @@ -441,7 +453,7 @@ error_ret: int find_type_by_name(const char *name, const char *type) { const struct dirent *ent; - int number, numstrlen; + int number, numstrlen, ret; FILE *nameFile; DIR *dp; @@ -459,9 +471,19 @@ int find_type_by_name(const char *name, const char *type) strcmp(ent->d_name, "..") != 0 && strlen(ent->d_name) > strlen(type) && strncmp(ent->d_name, type, strlen(type)) == 0) { - numstrlen = sscanf(ent->d_name + strlen(type), - "%d", - &number); + errno = 0; + ret = sscanf(ent->d_name + strlen(type), "%d", &number); + if (ret < 0) { + ret = -errno; + printf("failed to read element number\n"); + goto error_close_dir; + } else if (ret != 1) { + ret = -EIO; + printf("failed to match element number\n"); + goto error_close_dir; + } + + numstrlen = calc_digits(number); /* verify the next character is not a colon */ if (strncmp(ent->d_name + strlen(type) + numstrlen, ":", @@ -495,6 +517,11 @@ int find_type_by_name(const char *name, const char *type) } closedir(dp); return -ENODEV; + +error_close_dir: + if (closedir(dp) == -1) + perror("find_type_by_name(): Failed to close directory"); + return ret; } int _write_sysfs_int(char *filename, char *basedir, int val, int verify) -- 2.30.2