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/**
* @file config.c
*/
#include "spm.h"
/// Remove leading whitespace from a string
/// \param sptr pointer to string
/// \return pointer to first non-whitespace character in string
char *lstrip(char *sptr) {
while (isblank(*sptr)) {
sptr++;
}
return sptr;
}
/// Remove trailing whitespace from a string
/// \param sptr pointer to string
/// \return truncated string
char *strip(char *sptr) {
char *tmp = sptr + strlen(sptr) - 1;
while (isblank(*tmp) || *tmp == '\n') {
*tmp = '\0';
tmp--;
}
return sptr;
}
/// Determine if a string is empty
/// \param sptr pointer to string
/// \return 0=not empty, 1=empty
int isempty(char *sptr) {
char *tmp = sptr;
while (*tmp) {
if (!isblank(*tmp)) {
return 0;
}
tmp++;
}
return 1;
}
/// Determine if a string is encapsulated by quotes
/// \param sptr pointer to string
/// \return 0=not quoted, 1=quoted
int isquoted(char *sptr) {
const char *quotes = "'\"";
char *quote_open = strpbrk(sptr, quotes);
if (!quote_open) {
return 0;
}
char *quote_close = strpbrk(quote_open + 1, quotes);
if (!quote_close) {
return 0;
}
return 1;
}
ConfigItem **config_read(const char *filename) {
const char sep = '=';
char line[CONFIG_BUFFER_SIZE];
FILE *fp = fopen(filename, "r");
if (!fp) {
// errno will be set, so die, and let the caller handle it
return NULL;
}
int record_initial = 2;
ConfigItem **config = (ConfigItem **) calloc(record_initial, sizeof(ConfigItem *));
int record = 0;
while (fgets(line, sizeof(line), fp) != NULL) {
char *lptr = line;
// Remove leading space and newlines
lptr = lstrip(lptr);
// Remove trailing space and newlines
lptr = strip(lptr);
// Skip empty lines
if (isempty(lptr)) {
continue;
}
// Skip comment-only lines
if (*lptr == '#' || *lptr == ';') {
continue;
}
// Get a pointer to the key pair separator
char *sep_pos = strchr(lptr, sep);
if (!sep_pos) {
printf("invalid entry on line %d: missing '%c': '%s'\n", record, sep, lptr);
continue;
}
// These values are approximations. The real length(s) are recorded using strlen below.
// At most we'll lose a few heap bytes to whitespace, but it's better than allocating PATH_MAX or BUFSIZ
// for a measly ten byte string.
size_t key_length = strcspn(lptr, &sep);
size_t value_length = strlen(sep_pos);
// Allocate a ConfigItem record
config[record] = (ConfigItem *)calloc(1, sizeof(ConfigItem));
config[record]->key = (char *)calloc(key_length + 1, sizeof(char));
config[record]->value = (char *)calloc(value_length + 1, sizeof(char));
// Shortcut our array at this point. Things get pretty ugly otherwise.
char *key = config[record]->key;
char *value = config[record]->value;
// Copy the array pointers (used to populate config->key/value_length
char *key_orig = key;
char *value_orig = value;
// Populate the key and remove any trailing space
while (lptr != sep_pos) {
*key++ = *lptr++;
}
key = strip(key);
// We're at the separator now, so skip over it
lptr++;
// and remove any leading space
lptr = lstrip(lptr);
// Determine whether the string is surrounded by quotes, if so, get rid of them
if (isquoted(lptr)) {
// Move pointer beyond quote
lptr = strpbrk(lptr, "'\"") + 1;
// Terminate on closing quote
char *tmp = strpbrk(lptr, "'\"");
*tmp = '\0';
}
// Populate the value, and ignore any inline comments
while (*lptr) {
if (*lptr == '#' || *lptr == ';') {
// strip trailing whitespace where the comment is and stop processing
value = strip(value);
break;
}
*value++ = *lptr++;
}
// Populate length data
config[record]->key_length = strlen(key_orig);
config[record]->value_length = strlen(value_orig);
// increment record count
record++;
// Expand config by another record
config = (ConfigItem **)reallocarray(config, record + record_initial + 1, sizeof(ConfigItem *));
}
return config;
}
void config_free(ConfigItem **item) {
for (int i = 0; item[i] != NULL; i++) {
free(item[i]);
}
free(item);
}
/// If the configuration contains `key` return a pointer to that record
/// \param item pointer to array of config records
/// \param key search for key in config records
/// \return success=pointer to record, failure=NULL
ConfigItem *config_get(ConfigItem **item, const char *key) {
if (!item) {
return NULL;
}
for (int i = 0; item[i] != NULL; i++) {
if (!strcmp(item[i]->key, key)) {
return item[i];
}
}
return NULL;
}
void config_test(void) {
ConfigItem **config = config_read("program.conf");
printf("Data Parsed:\n");
for (int i = 0; config[i] != NULL; i++) {
printf("key: '%s', value: '%s'\n", config[i]->key, config[i]->value);
}
printf("Testing config_get():\n");
ConfigItem *cptr = NULL;
if ((cptr = config_get(config, "integer_value"))) {
printf("%s = %d\n", cptr->key, atoi(cptr->value));
}
if ((cptr = config_get(config, "float_value"))) {
printf("%s = %.3f\n", cptr->key, atof(cptr->value));
}
if ((cptr = config_get(config, "string_value"))) {
printf("%s = %s\n", cptr->key, cptr->value);
}
config_free(config);
}
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