Getting “Segmentation fault (core dumped)” after prompting user for input
Switch statement results in "Segmentation fault (core dumped)" regardless of the case.
I tried changing the data type of "command" but can't get any other result.
char command;
int temp;
while(1) {
printf("Enter command ('d'/'m'/'s'/'r'): ");
scanf("%c", command);
printf("n");
switch(command) {
case 'd' :
printf("display which employee (0-19)?n");
scanf("%i", temp);
//display(temp);
printf("displayed");
break;
case 'm' :
printf("modify which employee (0-19)?n");
scanf("%i", temp);
//modify(temp);
printf("modified");
break;
case 's' :
//save();
printf("saved");
break;
case 'r' :
//retrieve();
printf("retrieved");
break;
default :
printf("Command not recognizedn");
}
}
Expected to print the action according to the relevant case. Instead it just prints the "Segmentation fault (core dumped)" message regardless.
c
asked Dec 27 '18 at 20:17
user2324350
83
add a comment |
Switch statement results in "Segmentation fault (core dumped)" regardless of the case.
I tried changing the data type of "command" but can't get any other result.
char command;
int temp;
while(1) {
printf("Enter command ('d'/'m'/'s'/'r'): ");
scanf("%c", command);
printf("n");
switch(command) {
case 'd' :
printf("display which employee (0-19)?n");
scanf("%i", temp);
//display(temp);
printf("displayed");
break;
case 'm' :
printf("modify which employee (0-19)?n");
scanf("%i", temp);
//modify(temp);
printf("modified");
break;
case 's' :
//save();
printf("saved");
break;
case 'r' :
//retrieve();
printf("retrieved");
break;
default :
printf("Command not recognizedn");
}
}
Expected to print the action according to the relevant case. Instead it just prints the "Segmentation fault (core dumped)" message regardless.
c
asked Dec 27 '18 at 20:17
user2324350
83
3
scanf("%i", temp);-->scanf("%i", &temp);Sincetempis anintvariable, you need to provide&to store user input into it. Also read compiler warning carefully & solve them, don't ignore them.
– Achal
Dec 27 '18 at 20:18
2
also add a space before % and an ampersand before commandscanf(" %c", &command);
– xing
Dec 27 '18 at 20:19
add a comment |
Switch statement results in "Segmentation fault (core dumped)" regardless of the case.
I tried changing the data type of "command" but can't get any other result.
char command;
int temp;
while(1) {
printf("Enter command ('d'/'m'/'s'/'r'): ");
scanf("%c", command);
printf("n");
switch(command) {
case 'd' :
printf("display which employee (0-19)?n");
scanf("%i", temp);
//display(temp);
printf("displayed");
break;
case 'm' :
printf("modify which employee (0-19)?n");
scanf("%i", temp);
//modify(temp);
printf("modified");
break;
case 's' :
//save();
printf("saved");
break;
case 'r' :
//retrieve();
printf("retrieved");
break;
default :
printf("Command not recognizedn");
}
}
Expected to print the action according to the relevant case. Instead it just prints the "Segmentation fault (core dumped)" message regardless.
c
asked Dec 27 '18 at 20:17
user2324350
83
Switch statement results in "Segmentation fault (core dumped)" regardless of the case.
I tried changing the data type of "command" but can't get any other result.
char command;
int temp;
while(1) {
printf("Enter command ('d'/'m'/'s'/'r'): ");
scanf("%c", command);
printf("n");
switch(command) {
case 'd' :
printf("display which employee (0-19)?n");
scanf("%i", temp);
//display(temp);
printf("displayed");
break;
case 'm' :
printf("modify which employee (0-19)?n");
scanf("%i", temp);
//modify(temp);
printf("modified");
break;
case 's' :
//save();
printf("saved");
break;
case 'r' :
//retrieve();
printf("retrieved");
break;
default :
printf("Command not recognizedn");
}
}
Expected to print the action according to the relevant case. Instead it just prints the "Segmentation fault (core dumped)" message regardless.
c
c
asked Dec 27 '18 at 20:17
user2324350
83
asked Dec 27 '18 at 20:17
user2324350
83
asked Dec 27 '18 at 20:17
user2324350
83
asked Dec 27 '18 at 20:17
user2324350
83
asked Dec 27 '18 at 20:17
user2324350
83
83
3
scanf("%i", temp);-->scanf("%i", &temp);Sincetempis anintvariable, you need to provide&to store user input into it. Also read compiler warning carefully & solve them, don't ignore them.
– Achal
Dec 27 '18 at 20:18
2
also add a space before % and an ampersand before commandscanf(" %c", &command);
– xing
Dec 27 '18 at 20:19
add a comment |
3
scanf("%i", temp);-->scanf("%i", &temp);Sincetempis anintvariable, you need to provide&to store user input into it. Also read compiler warning carefully & solve them, don't ignore them.
– Achal
Dec 27 '18 at 20:18
2
also add a space before % and an ampersand before commandscanf(" %c", &command);
– xing
Dec 27 '18 at 20:19
3
3
scanf("%i", temp); --> scanf("%i", &temp); Since temp is an int variable, you need to provide & to store user input into it. Also read compiler warning carefully & solve them, don't ignore them.– Achal
Dec 27 '18 at 20:18
scanf("%i", temp); --> scanf("%i", &temp); Since temp is an int variable, you need to provide & to store user input into it. Also read compiler warning carefully & solve them, don't ignore them.– Achal
Dec 27 '18 at 20:18
2
2
also add a space before % and an ampersand before command
scanf(" %c", &command);Dec 27 '18 at 20:19
also add a space before % and an ampersand before command
scanf(" %c", &command);Dec 27 '18 at 20:19
add a comment |
1 Answer
1
active
oldest
votes
The %c format specifier expects the address of a char, i.e. a char * to be passed in. You're passing in a char instead. The same goes for %i and int further down. Using the wrong format specifier invokes undefined behaivor, which is in this case manifests as a crash.
You need to pass the address of the variables in question so that scanf can modify them. Also, for %c you should have a space in the format string before it to consume any whitespace left in the input buffer.
So you want:
scanf(" %c", &command);
And:
scanf("%i", &temp);
answered Dec 27 '18 at 20:20
dbush
93.1k12101134
add a comment |
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1 Answer
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active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
The %c format specifier expects the address of a char, i.e. a char * to be passed in. You're passing in a char instead. The same goes for %i and int further down. Using the wrong format specifier invokes undefined behaivor, which is in this case manifests as a crash.
You need to pass the address of the variables in question so that scanf can modify them. Also, for %c you should have a space in the format string before it to consume any whitespace left in the input buffer.
So you want:
scanf(" %c", &command);
And:
scanf("%i", &temp);
answered Dec 27 '18 at 20:20
dbush
93.1k12101134
add a comment |
The %c format specifier expects the address of a char, i.e. a char * to be passed in. You're passing in a char instead. The same goes for %i and int further down. Using the wrong format specifier invokes undefined behaivor, which is in this case manifests as a crash.
You need to pass the address of the variables in question so that scanf can modify them. Also, for %c you should have a space in the format string before it to consume any whitespace left in the input buffer.
So you want:
scanf(" %c", &command);
And:
scanf("%i", &temp);
answered Dec 27 '18 at 20:20
dbush
93.1k12101134
add a comment |
The %c format specifier expects the address of a char, i.e. a char * to be passed in. You're passing in a char instead. The same goes for %i and int further down. Using the wrong format specifier invokes undefined behaivor, which is in this case manifests as a crash.
You need to pass the address of the variables in question so that scanf can modify them. Also, for %c you should have a space in the format string before it to consume any whitespace left in the input buffer.
So you want:
scanf(" %c", &command);
And:
scanf("%i", &temp);
answered Dec 27 '18 at 20:20
dbush
93.1k12101134
The %c format specifier expects the address of a char, i.e. a char * to be passed in. You're passing in a char instead. The same goes for %i and int further down. Using the wrong format specifier invokes undefined behaivor, which is in this case manifests as a crash.
You need to pass the address of the variables in question so that scanf can modify them. Also, for %c you should have a space in the format string before it to consume any whitespace left in the input buffer.
So you want:
scanf(" %c", &command);
And:
scanf("%i", &temp);
answered Dec 27 '18 at 20:20
dbush
93.1k12101134
answered Dec 27 '18 at 20:20
dbush
93.1k12101134
answered Dec 27 '18 at 20:20
dbush
93.1k12101134
answered Dec 27 '18 at 20:20
dbush
93.1k12101134
93.1k12101134
add a comment |
add a comment |
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3
scanf("%i", temp);-->scanf("%i", &temp);Sincetempis anintvariable, you need to provide&to store user input into it. Also read compiler warning carefully & solve them, don't ignore them.– Achal
Dec 27 '18 at 20:18
2
also add a space before % and an ampersand before command
scanf(" %c", &command);– xing
Dec 27 '18 at 20:19