Cummulative work

1 files changed, 186 insertions, 0 deletions

diff --git a/config.c b/config.c
new file mode 100644
index 0000000..c2d905b
--- /dev/null
+++ b/config.c
@@ -0,0 +1,186 @@
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#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;
+}
+
+Config **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;
+    Config **config = (Config **) calloc(record_initial, sizeof(Config *));
+    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;
+        }
+
+        // Calculate key and value lengths dynamically
+        size_t key_length = strcspn(lptr, &sep);
+        size_t value_length = strlen(sep_pos);
+
+        // Allocate a Config record
+        config[record] = (Config *)calloc(1, sizeof(Config));
+        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;
+
+        // 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++;
+        }
+
+        // increment record count
+        record++;
+        // Expand config by another record
+        config = (Config **)reallocarray(config, record + record_initial + 1, sizeof(Config *));
+    }
+    return config;
+}
+
+void config_free(Config **config) {
+    for (int i = 0; config[i] != NULL; i++) {
+        free(config[i]);
+    }
+    free(config);
+}
+
+/// If the configuration contains `key` return a pointer to that record
+/// \param config pointer to array of config records
+/// \param key search for key in config records
+/// \return success=pointer to record, failure=NULL
+Config *config_get(Config **config, const char *key) {
+    for (int i = 0; config[i] != NULL; i++) {
+        if (!strcmp(config[i]->key, key)) {
+            return config[i];
+        }
+    }
+    return NULL;
+}
+
+void config_test(void) {
+    Config **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");
+    Config *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);
+}