What language should I use to write a text parser and display the results in a user friendly manner? [closed]

Answer 1

Whatever language your coworker used.

(I could tell you that any macro assembler will let you write code that would rip through your data, but seriously, are you going to spend months writing assembly just to save a few seconds of CPU time? Rewriting a program is fun but it's not practical.)

Whip out your profiler, point it at your horribly performing log parser, and fix the performance problems. If it's a common language, there will be people here who can help.

Answer 2

Hmmm, "go with what you know" was a good answer. Perl was designed for this sort of thing (but imo is well suited for simple parsing, but I'd personally avoid it for complex projects).

If it gets even a little complex, why not use a proper syntax and grammar set-up?

Lex & Yacc (or Flex & Bison) spring to mind, but personally I would always reach for Antlr

Define various "words" in terms of patterns (syntax), and rules to combine those words (grammar) and Antlr will spit out a program to parse your input (you can have the program in Java, C, C++ and more (you are worried about parse time, so choose a compiled language, of course)).

I personally find it tedious to hand-craft parsers, and even more tedious to debug them, but AntlrWorks is a lovely IDE which really makes it a piece of cake ...

That bit at the bottom is defining a grammar rule.

If you mess up your grammar rules, you will be informed. This is not the case with hand-crafted parsers, where you just scratch your body part and wonder about the "strange results"...

Check it out. Even if you think your project is trivial now, it may well grow. And if you have any interest in parsing you do owe it to yourself to at least be familiar with lex/yacc, but especially Antlr(Works)

Answer 3

Maybe a finished product such as the MS LogParser (usage podcast here) may do what you need and it's free.

Answer 4

Perl is good for text processing.

A number of very good text processing programs have been written in Perl. Ack (a grep replacement) is one.

Answer 5

Sounds like a job for Perl, much as I don't particularly care for it as a language myself. ActivePerl is a reasonable distribution of Perl for Windows.

Answer 6

c/c++ or java... for c/c++ i have snippet that might help you:

FILE *f = fopen(file, "rb");
if(f == NULL) {
    return DBDEMON_OPEN_ERROR; // open fail
}

for(int i = 0; feof(f) == 0; i++)

{

fscanf(f,"%d %s %s %c\n",  &db[i].id, &db[i].name[0], &db[i].uid[0], &db[i].priviledge);

db_size++;

}

fclose(f);

this is reading a file with the following format:

int string string char

1 SOMETHING ANYTHING Z

to a struct define as follows:

typedef struct {

    unsigned int    id;
    char        name[DBDEMON_NAME_MAXSIZE];
    char        uid[DBDEMON_UID_MAXSIZE];
    char        priviledge;
} DATABASE;

Use fscanf with care, since no types are checked, etc, it can result in errors. But I think this is pretty efficient.