Dear all , I try with this segment to open a file through passing the file name with argv. but the file couldn't be open. please comment :
thanksCode:#include <iostream.h> ifstream input_code; int main(int argc, char argv[]) { if(argc == 1) {cout << "You need to pass in a file name to the program via the command line\n"; cin.get(); return 1;} else input_code.open(argv); return 0; }
This:Should be:Code:else input_code.open(argv);Code:else input_code.open(argv[2]);
> int main(int argc, char argv[])
It's
int main(int argc, char *argv[])
> if(argc == 1)
< 2 would be a safer test
> input_code.open(argv);
With main fixed, this would be
input_code.open(argv[1]);
argv[0] is typically the program name
argv[1] is the first command line parameter
argv[argc] is NULL
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
Yeah, [1], not [2]. Sorry, I'm tired and not thinking straight
yes its successed , thank you so so much
Do not include iostream.h. It will almost certainly include deprectated headers. Include <iostream>.
Originally Posted by brewbuck:
Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.
>> Do not include iostream.h. It will almost certainly include deprectated headers. Include <iostream>
Deprecated headers and features are discouraged but still standard and will still work on standard compliant compilers. <iostream.h> should not be used because it is completely non-standard, and does not work on many modern compilers.
