| summaryrefslogtreecommitdiff |
diff options
Diffstat (limited to 'src/config.c')
| -rw-r--r-- | src/config.c | 224 |
1 files changed, 171 insertions, 53 deletions
diff --git a/src/config.c b/src/config.c index 1699811..2c860b9 100644 --- a/src/config.c +++ b/src/config.c @@ -6,9 +6,30 @@ #include "axis.h" #include "config.h" +/* + * "errno is never set to zero by any system call or library function." + * This file makes use of this, by setting it to zero and checking if + * it was modified after calling an function (I'm guessing this is common + * practice, but I think it's worth explaining). + * Following the principle of least astonishment, if a function sets errno to + * zero, it will not return before setting it back either to its previous + * value or to a arbitrary nonzero value. + */ + +/* + * Returns -1 on error, + * 0 on EOF, + * 1 on newline. + */ static int reach_next_line_or_eof (FILE * const f) { + int prev_errno; char c; + + prev_errno = errno; + + errno = 0; + c = getc(f); while ((c != '\n') && c != EOF) @@ -16,15 +37,28 @@ static int reach_next_line_or_eof (FILE * const f) c = getc(f); } - if (c == EOF) + if (errno != 0) { + errno = prev_errno; + return -1; } - return 0; + errno = prev_errno; + + if (c == EOF) + { + return 0; + } + + return 1; } -static int all_axis_are_configured (const int * const axis_is_configured) +/* + * Returns -1 on if an axis has not been configured, + * 0 otherwise. + */ +static int all_axes_are_configured (const int * const axis_is_configured) { int i; @@ -45,15 +79,21 @@ static int all_axis_are_configured (const int * const axis_is_configured) return 0; } +/* + * Returns -1 on (fatal) error, + * 0 on succes. + * On failure, 'axis_is_configured' is untouched. + * On success, the corresponding 'axis_is_configured' is set to 1. + */ static int parse_axis_configuration_line ( struct relabsd_config * const conf, FILE * const f, int * const axis_is_configured, - char * const buffer + const char * const buffer ) { - int valc; + int valc, prev_errno; enum relabsd_axis axis; axis = relabsd_axis_name_to_enum(buffer); @@ -69,25 +109,42 @@ static int parse_axis_configuration_line return -1; } - valc = - fscanf - ( - f, - "%d %d %d %d %d", - &(conf->axis[axis].min), - &(conf->axis[axis].max), - &(conf->axis[axis].fuzz), - &(conf->axis[axis].flat), - &(conf->axis[axis].resolution) - ); + prev_errno = errno; + errno = 0; + + valc = + fscanf + ( + f, + "%d %d %d %d %d", + &(conf->axis[axis].min), + &(conf->axis[axis].max), + &(conf->axis[axis].fuzz), + &(conf->axis[axis].flat), + &(conf->axis[axis].resolution) + ); if (valc == EOF) { - _FATAL - ( - "[CONFIG] Unexpected end of file while reading axis '%s'.", - buffer - ); + if (errno == 0) + { + _FATAL + ( + "[CONFIG] Unexpected end of file while reading axis '%s'.", + buffer + ); + } + else + { + _FATAL + ( + "[CONFIG] An error occured while reading axis '%s': %s.", + buffer, + strerror(errno) + ); + } + + errno = prev_errno; return -1; } @@ -99,13 +156,57 @@ static int parse_axis_configuration_line buffer ); + errno = prev_errno; + return -1; } + errno = prev_errno; + axis_is_configured[axis] = 1; + return 0; } +/* + * Returns -1 on (fatal) error, + * 0 on EOF, + * 1 on newline. + */ +static int read_config_line +( + struct relabsd_config * const conf, + FILE * const f, + int * const axis_is_configured, + const char * const prefix +) +{ + if (!_IS_PREFIX("#", prefix)) + { + if + ( + parse_axis_configuration_line + ( + conf, + f, + axis_is_configured, + prefix + ) + < 0 + ) + { + /* Fatal error. */ + return -1; + } + } + + return reach_next_line_or_eof(f); +} + +/* + * Returns -1 on (fatal) error, + * 0 on success. + */ static int read_config_file ( struct relabsd_config * const conf, @@ -115,11 +216,11 @@ static int read_config_file FILE * f; int axis_is_configured[6]; char buffer[3]; - int test; + int continue_reading, prev_errno; buffer[2] = '\0'; - memset(axis_is_configured, 0, 6 * sizeof(int)); + memset(axis_is_configured, 0, (6 * sizeof(int))); f = fopen(filename, "r"); @@ -134,43 +235,37 @@ static int read_config_file return -1; } + prev_errno = errno; errno = 0; - while ((test = fscanf(f, "%2s", buffer)) > 0) + continue_reading = 1; + + while ((continue_reading == 1) && (fscanf(f, "%2s", buffer) != EOF)) { - if (_IS_PREFIX("#", buffer)) - { - if (reach_next_line_or_eof(f) < 0) - { - break; - } - } - else + switch (read_config_line(conf, f, axis_is_configured, buffer)) { - if - ( - parse_axis_configuration_line - ( - conf, - f, - axis_is_configured, - buffer - ) - < 0 - ) - { + case 1: + /* Everything is going well. */ break; - } - if (reach_next_line_or_eof(f) < 0) - { + case 0: + /* EOF reached. */ + continue_reading = 0; break; - } + + case -1: + /* A fatal error occured. */ + errno = prev_errno; + + fclose(f); + return -1; } } - if (test < 0 && errno != 0) + if (errno != 0) { + /* An error happened in the while loop condition. */ + _FATAL ( "[CONFIG] Error while reading file: %s, last read '%s'.", @@ -178,14 +273,18 @@ static int read_config_file buffer ); + errno = prev_errno; + fclose(f); return -1; } + errno = prev_errno; + fclose(f); - if (all_axis_are_configured(axis_is_configured) < 0) + if (all_axes_are_configured(axis_is_configured) < 0) { return -1; } @@ -193,11 +292,14 @@ static int read_config_file return 0; } -int relabsd_config_parse +/* + * Returns -1 on (fatal) error, + * 0 on valid usage. + */ +static int check_usage ( - struct relabsd_config * const conf, int const argc, - char ** const argv + char * const * const argv ) { if ((argc < 3) || (argc > 4)) @@ -211,6 +313,21 @@ int relabsd_config_parse return -1; } + return 0; +} + +int relabsd_config_parse +( + struct relabsd_config * const conf, + int const argc, + char * const * const argv +) +{ + if (check_usage(argc, argv) < 0) + { + return -1; + } + if (argc == 3) { conf->device_name = "relabsd device"; @@ -237,6 +354,7 @@ int relabsd_config_allows int const value ) { + /* TODO */ return 1; }; |