Parse string into array based on spaces or “double quotes strings”

Question

Im trying to take a user input string and parse is into an array called char *entire_line[100]; where each word is put at a different index of the array but if a part of the str

Answer 1

I wrote a qtok function some time ago that reads quoted words from a string. It's not a state machine and it doesn't make you an array but it's trivial to put the resulting tokens into one. It also handles escaped quotes and trailing and leading spaces:

#include 
#include 
#include 

// Strips backslashes from quotes
char *unescapeToken(char *token)
{
    char *in = token;
    char *out = token;

    while (*in)
    {
        assert(in >= out);

        if ((in[0] == '\\') && (in[1] == '"'))
        {
            *out = in[1];
            out++;
            in += 2;
        }
        else
        {
            *out = *in;
            out++;
            in++; 
        }
    }
    *out = 0;
    return token;
}

// Returns the end of the token, without chaning it.
char *qtok(char *str, char **next)
{
    char *current = str;
    char *start = str;
    int isQuoted = 0;

    // Eat beginning whitespace.
    while (*current && isspace(*current)) current++;
    start = current;

    if (*current == '"')
    {
        isQuoted = 1;
        // Quoted token
        current++; // Skip the beginning quote.
        start = current;
        for (;;)
        {
            // Go till we find a quote or the end of string.
            while (*current && (*current != '"')) current++;
            if (!*current) 
            {
                // Reached the end of the string.
                goto finalize;
            }
            if (*(current - 1) == '\\')
            {
                // Escaped quote keep going.
                current++;
                continue;
            }
            // Reached the ending quote.
            goto finalize; 
        }
    }
    // Not quoted so run till we see a space.
    while (*current && !isspace(*current)) current++;
finalize:
    if (*current)
    {
        // Close token if not closed already.
        *current = 0;
        current++;
        // Eat trailing whitespace.
        while (*current && isspace(*current)) current++;
    }
    *next = current;

    return isQuoted ? unescapeToken(start) : start;
}

int main()
{
    char text[] = "   \"some text in quotes\"    plus   four simple words p\"lus something strange\" \"Then some quoted \\\"words\\\", and backslashes: \\ \\ \"  Escapes only work insi\\\"de q\\\"uoted strings\\\"   ";

    char *pText = text;

    printf("Original: '%s'\n", text);
    while (*pText)
    {
        printf("'%s'\n", qtok(pText, &pText));
    }

}

Outputs:

Original: '   "some text in quotes"    plus   four simple words p"lus something strange" "Then some quoted \"words\", and backslashes: \ \ "  Escapes only work insi\"de q\"uoted strings\"   '
'some text in quotes'
'plus'
'four'
'simple'
'words'
'p"lus'
'something'
'strange"'
'Then some quoted "words", and backslashes: \ \ '
'Escapes'
'only'
'work'
'insi\"de'
'q\"uoted'
'strings\"'