util.c File Reference

implement utility functions from util.h More...

#include "debugmalloc.h"
#include <string.h>
#include <stdlib.h>
#include "util.h"
#include "logging.h"

Go to the source code of this file.

Functions
char *	util_find_string_segment (char *ptr)
	find pointer to next space or null in string More...
int	util_match_char (char a, char b)
	Case-insensitive character compare. More...
int	util_match_string (char *first, char *second, int count)
	case-insensitive memcmp More...
char **	util_split_string (char *str, int *n)
	split a string into segments on spaces More...

Detailed Description

implement utility functions from util.h

See also

util.h

Definition in file util.c.

Function Documentation

util_find_string_segment()

char* util_find_string_segment

(

char *

ptr

)

find pointer to next space or null in string

Parameters

ptr	string to search in

Returns

address of next space or null character in string

Definition at line 15 of file util.c.

                                          {
    char* end = ptr;
    while (*end != ' ' && *end != '\0') end++;
    return end;
}

util_match_char()

int util_match_char	(	char	a,
		char	b
	)

Case-insensitive character compare.

Parameters

a	first char to compare
b	second char to compare

Returns

0 if the two characters match, 1 otherwise

Definition at line 21 of file util.c.

                                    {
    return a == b ||
        (
            (
                (('a' <= a && a <= 'z') || ('A' <= a && a <= 'Z')) && // a is a letter
                (('a' <= b && b <= 'z') || ('A' <= b && b <= 'Z'))    // b is a letter
                ) &&
            (a - b == 'A' - 'a' || a - b == 'a' - 'A')
            );
}

Referenced by Token::token_get_addressmode(), and util_match_string().

util_match_string()

int util_match_string	(	char *	first,
		char *	second,
		int	count
	)

case-insensitive memcmp

Parameters

count	how many bytes to match
first	first string to compare
second	second string to compare

Returns

0 if the strings match, 1 otherwise

Definition at line 32 of file util.c.

                                                            {
    for (int i = 0; i < count; i++) {
        if (!util_match_char(first[i], second[i])) return 1;
    }
    return 0;
}

References util_match_char().

Referenced by directive_compile(), and instruction_find().

util_split_string()

char** util_split_string	(	char *	str,
		int *	n
	)

split a string into segments on spaces

Parameters

str	string to split
n	int pointer to return segment count to

Returns

an array of substrings

Uses a not-so-nice trick to enable easier handling
The returned *char[] also contains a buffer with the actual substring data
This also means simply freeing it is all what is needed to be done on the caller side

Definition at line 39 of file util.c.

                                            {
    // function to split a string into substrings on spaces
    // uses an ugly trick to avoid multiple buffers
    // (we NEED to store a copy of the original data bc we must write 0 terminators)
    int l = strlen(str);
 
    // count segments
    int m = 1;
    for (int i = 0; i < l; i++)
        if (str[i] == ' ') m++;
    *n = m;
 
    // the buffers stores the *char[]-s and then the copy of the data
    char** r = malloc(sizeof(char*) * m + l + 1);
 
    char* buf = (char*)r + sizeof(char*) * m;
    strcpy(buf, str);
 
    // first segemtn is the begining of the string
    r[0] = buf;
    // fill the table and write 0 terminators
    int j = 1;
    for (int i = 0; i < l; i++)
        if (str[i] == ' ') {
            buf[i] = 0;
            r[j++] = buf + i + 1;
        }
    return r;
}

Referenced by compile_data(), and compile_pad().