trouble with arguments in main method

Hi,

I'm having some trouble with my C assignment. My assignment is based on an unix program that performs translations, deletions, uppercase, lowercase, and squeezing.

My basic problem right now is my main method. I want have an output like this to access the various options listed above.
a -u<test.txt> output.txt

-a is used to run the program in gvim

but I cannot get this output. I get a message saying: tr: invalid option --u

Here's my code for the main method:

Code:

---

int main(int argc, char *argv[])
{
        int i;
        FILE *fp;
        char varchar;
        char s[BUFSIZE];

        if(argc > 2)  /*two arguments are allowed*/
        {
                fprintf(stderr, "usage:%s file....\n", argv[0]);
                return 1;
        }
        if((fp = fopen(argv[0], "w"))==0)
        {
                perror("fopen");
                return 1;
        }
        for(i=0; i<argc; i++)
        {
                if(argv[i][0] == '-')
                {
                        if(argv[i][1] == 'u')
                                upper(s);
                        if(argv[i][1] == 'l')
                                lower(s);
                        if(varchar == 'h')
                                display(s);
                        else
                                fprintf(stderr, "invalid input\n");
                            fprintf(stderr, "Please try 'tr -h' for help\n");
                }
                else
                        fprintf(stderr, "first argument problem\n");
        }
        fclose(fp);
        return 0;
}

---

I do not understand your explanaition
do you plan to run the program as

a -u<test.txt> output.txt

in this case
argc = 3
argv[0] = "a"
argv[1]="-u<test.txt>"
argv[2]="output.txt"

But your code shows something different

...

Code:

---

if(varchar == 'h')

---

varchar is not initialized. This line is executed always (should it be?) with unpredictable results

fprintf(stderr, "Please try 'tr -h' for help\n");
this line is always executed also inside the codition branch if(argv[i][0] == '-')

Quote:

---

Originally Posted by vart

I do not understand your explanaition
do you plan to run the program as

a -u<test.txt> output.txt

in this case
argc = 3
argv[0] = "a"
argv[1]="-u<test.txt>"
argv[2]="output.txt"

---

"a" - is what I use to run the program, I used a compiler from gvim

argv[0]="-"
argv[1]="u<test.txt>"
argv[2]="output.txt"

this is what I'm trying to do right now

I actually have moved onto a new design in my code, so far its a bit successful

Code:

---

int main(int argc, char *argv[])
{
        int i;
        char s[BUFSIZE];
        FILE *fp;

        if(argc != 2 && argc != 3)
        {
                fprintf(stderr, "usage:%s file....\n", argv[0]);
                return 1;
        }
       
        for(i=1; i<argc; i++)
        {
                if(argc == 2)
                {

                        if(strcmp(argv[1], "-l") == 0)
                        {
                                lower(s);
                        }
                        else if(strcmp(argv[1], "-u") == 0)
                        {
                                upper(fp);
                        }
                        else
                        {
                                fprintf(stderr, "ok\n");
                        }
                }
                else
                        fprintf(stderr, "ok\n");
        }
      return 0;
}

---

argv[0] is a program name (with or without location depending on the environment)
"-" to be reported as full argument should be delimited with space from the next part...

have you tested your settings using simple program:

Code:

---

int main(int argc, char* argv[])
{
  int i;
  printf("Number of args %d\n", argc);
  for(i=0; i<argc;i++)
      printf("%d: <%s>\n", i,argv[i]);
}

---

???