a C input question..

tmike · #1 19-Sep-2003, 00:44

Hi, guys...I have a question about keyboard input in C

let's say I have a program which allows user to type in command
commands are in the form:
command parameter1 parameter2...etc

since commands have different # of parameters..I'll need to use fgets or gets to get the whole command string and parse it...

also, I'll allow user to continue inputing command except when they type in "quit"

this is how I do it..

CPP / C++ / C Code:

char command[100], *com;

for(;; )
{
       com = fgets(command, 50, stdin);
       // this line just get the whole command as a string

      if(strcasecmp(command, "quit") == 0)
			break;

      execute(com);
      // this is a function which parse the whole command string
         and  execute approapriate functions...

}

but here comes a problem...
if a user didn't type anything, but just hit ENTER....it'll have a segmentation fault, becuz the fgets will have some problem with nothing entered....I thought that the fgets will return NULL..so I can use that condition to detect this kind of situation and just loop around again.....but it doesn't happen that way...

I was wondering if there's a way I can do to make my program keeps waiting for user command, even if the user decided to press a whole lot of ENTERs, it'll just loop around..

tks....

tmike · #2 19-Sep-2003, 01:53

ha....I figured it out...
sorry about the post.....

Garth Farley · #3 19-Sep-2003, 03:39

No worries! You wanna say how you fixed it?

GF

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