+/* src/common/parse_file.c */
+
+#define _POSIX_C_SOURCE 200809L /* strdup() */
+#include "parse_file.h"
+#include <stddef.h> /* NULL */ // size_t
+#include <stdio.h> /* FILE, sprintf() */
+#include <stdint.h> /* uint8_t, uint32_t */
+#include <stdlib.h> /* free() */ // atoi()
+#include <string.h> /* strchr, strdup(), strlen() */ // strcmp()
+#include <unistd.h> /* access(), F_OK */
+#include "err_try_fgets.h" /* err_line(), err_try_fgets(),
+ * reset_err_try_fgets_counter()
+ */
+#include "readwrite.h" /* try_fopen(),try_fclose(), textfile_width() */
+#include "rexit.h" /* exit_err() */
+#include "try_malloc.h" /* try_malloc() */
+
+
+
+/* Return next token from "line" or NULL if none is found. Tokens either a)
+ * start at the first non-whitespace character and end before the next
+ * whitespace character after that; or b) if the first non-whitespace character
+ * is a single quote followed by at least one other single quote some time later
+ * on the line, the token starts after that first single quote and ends before
+ * the second, with the next token_from_line() call starting its token search
+ * after that second quote. The only way to return an empty string (instead of
+ * NULL) as a token is to delimit the token by two succeeding single quotes.
+ * */
+static char * token_from_line(char * line);
+
+/* Determines the end of the token_from_line() token. */
+static void set_token_end(char ** start, char ** limit_char);
+
+
+
+static char * token_from_line(char * line)
+{
+ static char * final_char = NULL;
+ static char * limit_char = NULL;
+ char * start = limit_char + 1;
+ if (line)
+ {
+ start = line;
+ limit_char = start;
+ final_char = &(line[strlen(line)]);
+ if ('\n' == *(final_char - 1))
+ {
+ *(--final_char) = '\0';
+ }
+ }
+ uint8_t empty = 1;
+ uint32_t i;
+ for (i = 0; '\0' != start[i]; i++)
+ {
+ if (' ' != start[i] && '\t' != start[i])
+ {
+ start = &start[i];
+ empty = 0;
+ break;
+ }
+ }
+ if (empty)
+ {
+ return start = NULL;
+ }
+ set_token_end(&start, &limit_char);
+ return start;
+}
+
+
+
+static void set_token_end(char ** start, char ** limit_char)
+{
+ char * end_quote = ('\'' == (*start)[0]) ? strchr(*start + 1, '\'') : NULL;
+ *start = (end_quote) ? *start + 1 : *start;
+ if (end_quote)
+ {
+ *end_quote = '\0';
+ *limit_char = end_quote;
+ return;
+ }
+ char * space = strchr(*start, ' ');
+ char * tab = strchr(*start, '\t');
+ space = (!space || (tab && tab < space)) ? tab : space;
+ if (space)
+ {
+ * space = '\0';
+ }
+ *limit_char = strchr(*start, '\0');
+}
+
+
+
+extern void set_uint8(struct Context * context, uint8_t * target)
+{
+ char * err_uint8 = "Value not unsigned decimal number between 0 and 255.";
+ uint8_t i;
+ uint8_t is_uint8 = 1;
+ for (i = 0; '\0' != context->token1[i]; i++)
+ {
+ if (i > 2 || '0' > context->token1[i] || '9' < context->token1[i])
+ {
+ is_uint8 = 0;
+ }
+ }
+ if (is_uint8 && atoi(context->token1) > UINT8_MAX)
+ {
+ is_uint8 = 0;
+ }
+ err_line(!(is_uint8), context->line, context->err_pre, err_uint8);
+ *target = atoi(context->token1);
+}
+
+
+
+extern uint8_t set_val(struct Context * context, char * comparand,
+ uint8_t * flags, uint8_t set_flag, char type,
+ char * element)
+{
+ char * err_out = "Outside appropriate definition's context.";
+ char * err_singlechar = "Value must be single ASCII character.";
+ if (!strcmp(context->token0, comparand))
+ {
+ err_line(!(* flags & EDIT_STARTED),
+ context->line, context->err_pre, err_out);
+ * flags = * flags | set_flag;
+ if ('s' == type)
+ {
+ * (char **) element = strdup(context->token1);
+ }
+ else if ('c' == type)
+ {
+ err_line(1 != strlen(context->token1),
+ context->line, context->err_pre, err_singlechar);
+ * element = (context->token1)[0];
+ }
+ else if ('8' == type)
+ {
+ set_uint8(context, (uint8_t *) element);
+ }
+ return 1;
+ }
+ return 0;
+}
+
+
+
+extern void parse_file(char * path, void (* token_to_entry) (struct Context *))
+{
+ char * f_name = "read_new_config_file()";
+ struct Context context;
+ char * err_pre_prefix = "Failed reading config file: \"";
+ char * err_pre_affix = "\". ";
+ context.err_pre = try_malloc(strlen(err_pre_prefix) + strlen(path)
+ + strlen(err_pre_affix) + 1, f_name);
+ sprintf(context.err_pre, "%s%s%s", err_pre_prefix, path, err_pre_affix);
+ exit_err(access(path, F_OK), context.err_pre);
+ FILE * file = try_fopen(path, "r", f_name);
+ uint32_t linemax = textfile_width(file);
+ context.line = try_malloc(linemax + 1, f_name);
+ reset_err_try_fgets_counter();
+ err_line(0 == linemax, context.line, context.err_pre, "File is empty.");
+ context.token0 = NULL; /* For token_to_entry() if while() stagnates. */
+ char * err_val = "No value given.";
+ char * err_many = "Too many values.";
+ while (err_try_fgets(context.line, linemax + 1, file, context.err_pre, ""))
+ {
+ char * line_copy = strdup(context.line);
+ context.token0 = token_from_line(line_copy);
+ if (context.token0)
+ {
+ err_line(0 == (context.token1 = token_from_line(NULL)),
+ context.line, context.err_pre, err_val);
+ err_line(NULL != token_from_line(NULL),
+ context.line, context.err_pre, err_many);
+ token_to_entry(&context);
+ context.token0 = NULL;
+ }
+ free(line_copy);
+ }
+ token_to_entry(&context);
+ try_fclose(file, f_name);
+ free(context.line);
+ free(context.err_pre);
+}
projects / plomrogue / commitdiff