no idea

[wingnut2626]

#include <stdio.h>
#include <string.h>


int main(int argc, char *argv[])
{


int argument, letter_position, number_of_characters;
char current_character;


for(argument = 1; argument <= argc; argument++){
number_of_characters = strlen(argv[argument]);
printf("%d number of characters debug", number_of_characters);
getchar();
for(letter_position = 0; argv[argument][letter_position] != '\0'; letter_position++){
printf("starting loop, position %d", letter_position + 1);
getchar();
current_character = argv[argument][letter_position];
if(current_character == 'A' || 'a'){
printf("%d letter of %d argument is A\n", letter_position + 1, argument);
}
else if(current_character == 'E' || 'e'){
printf("%d letter of %d argument is E\n", letter_position + 1, argument);
}
else if(current_character == 'I' || 'i'){
printf("%d letter of %d argument is I\n", letter_position + 1, argument);
}
else if(current_character == 'O' || 'o'){
printf("%d letter of %d argument is O\n", letter_position + 1, argument);
}
else if(current_character =='U' || 'u'){
printf("%d letter of %d argument is U\n", letter_position + 1, argument);
}
}
}



return 0;
}




Basically im trying to filter through each letter of each argument and spit out the vowels. I even included debug statements, cannot for the life of me understand why this is the output:


./test13 this is a string
4 number of characters debug
starting loop, position 1
1 letter of 1 argument is A
starting loop, position 2
2 letter of 1 argument is A
starting loop, position 3
3 letter of 1 argument is A
starting loop, position 4
4 letter of 1 argument is A
2 number of characters debug
starting loop, position 1
1 letter of 2 argument is A
starting loop, position 2
2 letter of 2 argument is A
1 number of characters debug
starting loop, position 1
1 letter of 3 argument is A
6 number of characters debug
starting loop, position 1
1 letter of 4 argument is A
starting loop, position 2
2 letter of 4 argument is A
starting loop, position 3
3 letter of 4 argument is A
starting loop, position 4
4 letter of 4 argument is A
starting loop, position 5
5 letter of 4 argument is A
starting loop, position 6
6 letter of 4 argument is A
zsh: segmentation fault ./test13 this is a string




what is going on?

[wingnut2626]

Here i added more debugging:


#include <stdio.h>
#include <string.h>


int main(int argc, char *argv[])
{


int argument, letter_position, number_of_characters;
char current_character;


for(argument = 1; argument <= argc; argument++){
number_of_characters = strlen(argv[argument]);
printf("%d number of characters debug", number_of_characters);
getchar();
for(letter_position = 0; argv[argument][letter_position] != '\0'; letter_position++){
printf("starting loop, position %d", letter_position + 1);
getchar();
current_character = argv[argument][letter_position];
printf("%c", current_character);
getchar();
if(current_character == 'A' || 'a'){
printf("%d letter of %d argument is A\n", letter_position + 1, argument);
}
else if(current_character == 'E' || 'e'){
printf("%d letter of %d argument is E\n", letter_position + 1, argument);
}
else if(current_character == 'I' || 'i'){
printf("%d letter of %d argument is I\n", letter_position + 1, argument);
}
else if(current_character == 'O' || 'o'){
printf("%d letter of %d argument is O\n", letter_position + 1, argument);
}
else if(current_character =='U' || 'u'){
printf("%d letter of %d argument is U\n", letter_position + 1, argument);
}
}
}



return 0;
}


here is the output:


./test13 this is a string
4 number of characters debug
starting loop, position 1
t
1 letter of 1 argument is A
starting loop, position 2
h
2 letter of 1 argument is A
starting loop, position 3
i
3 letter of 1 argument is A
starting loop, position 4
s
4 letter of 1 argument is A
2 number of characters debug
starting loop, position 1
i
1 letter of 2 argument is A
starting loop, position 2
s
2 letter of 2 argument is A
1 number of characters debug
starting loop, position 1
a
1 letter of 3 argument is A
6 number of characters debug
starting loop, position 1
s
1 letter of 4 argument is A
starting loop, position 2
t
2 letter of 4 argument is A
starting loop, position 3
r
3 letter of 4 argument is A
starting loop, position 4
i
4 letter of 4 argument is A
starting loop, position 5
n
5 letter of 4 argument is A
starting loop, position 6
g
6 letter of 4 argument is A
zsh: segmentation fault ./test13 this is a string

everything is going as expected, except each current_char is interpreted as an A or a....

[steeldriver]

current_character == 'A' || 'a'

... does not mean what you think it means (HINT: is the value of 'a' true or false?)

[wingnut2626]

oh i think i know what you are getting at....

[wingnut2626]

Thought i did but i didnt. I tried putting the characters in double quotes. wont compile...
how come this works?


include <stdio.h>


int main(int argc, char *argv[])
{
if(argc != 2){
printf("ERROR : You need one argument.\n");
return 1;
}


int i = 0;
for(i = 0; argv[1][i] != '\0'; i++){
char letter = argv[1][i];

switch(letter){
case 'a':
case 'A':
printf("%d: 'A'\n", i);
break;


case 'e':
case 'E':
printf("%d: 'E'\n", i);
break;


case 'i':
case 'I':
printf("%d: 'I'\n", i);
break;


case 'o':
case 'O':
printf("%d: 'O'\n", i);
break;


case 'u':
case 'U':
printf("%d: 'U'\n", i);
break;


case 'y':
case 'Y':
if(i > 2){
printf("%d: 'Y'\n", i);
}
break;

default:
printf("%d: %c is not a vowel\n", i , letter);
}
}
return 0;
}




That one does the job but the other one does not.....

[wingnut2626]

I GOT IT. needed to do some research. looks like i needed

if(current_character == 'A' || current_character == 'a')

going to try this then either mark it as solved or whine some more

[wingnut2626]

ok i got it to do what i wanted, however there is still a segmentation fault at the end....any hints?

[steeldriver]

at a guess, because argv is indexed from 0 (the name by which the program was invoked) to argc-1 - so your outermost loop likely needs to run from 1 to argument<argc (rather than argument<=argc)

[wingnut2626]

let me digest that...

[wingnut2626]

solved. I am going to try to understand what you said steeldriver

[steeldriver]

well if you start counting your fingers starting from 0 what number to you end with? how many fingers do you have?