Question

I have a simple regex to check if a function name, lies within a block of C-code (the actual name finding code is written in Java).
For this example, the function name i’m trying to find is called putFillerData. The code block looks like this:

static void fillerSwapByteOrder(int t_database, tag_t t_message, char* data_buff, int* pos)
{
short data_length = trxDBGetNodeSize(t_database);

if (!data_length) return;

char *data = umalloc(data_length);

if (data_length == sizeof(short))
{
    short s_data = 0;
    shareGReadData(t_database, &s_data);
    short nbo_data = htons(s_data);
    memcpy(data, &nbo_data, sizeof(short));
}
else if (data_length == sizeof(int))
{
    int s_data = 0;
    shareGReadData(t_database, &s_data);
    int nbo_data = htonl(s_data);
    memcpy(data, &nbo_data, sizeof(int));
}
else
{
    ufree(data);
    return;
}

putFillerData(t_message, data, data_length, data_buff, pos);

ufree(data);
}

The regex statement i’m using looks like this:

Pattern.matches("\\b" + Pattern.quote(name) + "\\b", code);

However, this always return false… Why?

The reason I’m using this regex, is becouse .contains finds substrings as well, which is not what I want…

Answer 1

.matches() only returns True if the entire string matches the regex.

You want to use the .find() method:

Pattern regex = Pattern.compile("\\b" + Pattern.quote(name) + "\\b");
Matcher regexMatcher = regex.matcher(subjectString);
foundMatch = regexMatcher.find();

_{Also, \b only matches between alphanumeric and non-alphanumeric characters. So it should be fine if your name is putFillerData, but not if it’s something like putFillerData().}