Question

I’m working on a C program that get the command line arguments and append to them a file extension.

The execution will be something like this:
>myprogram file1 file2
and will execute another program that will use as argument file1.txt and file2.txt.
I tried doing that would add the extension and run one command (s1 is the path and s2 is argv[i] on a loop:

int getfile(char *s1, char *s2){
char *str2 = malloc(sizeof(s2)+3);
strcpy(str2,s2);
strcat(str2,".txt");
execl(s1,"program",str2,NULL);
exit(0); 
}

The function will run the program for one file (>program file1.txt and >program file2.txt), but I will need to find a way to run it this way (>program file1.txt file2.txt).

I tried to modify argv directly, but I was unsuccessful.

Any advise?

Answer 1

Try this code:

int main(int argc, char *argv[])
{
   char *buffer;
   char command[512];
   int i = 1;
   for(i = 1; i < argc; i++){
     buffer = malloc(strlen(argv[i]) + 5);
     strcpy(buffer,argv[i]);
     strcat(buffer,".txt");
     sprintf(command,"touch %s\0",buffer);
     system(command);
     free(buffer);
  }
  return 0;
}

A simple program that has no error checking, and I like to explicitly add the string terminator.