sscanf: parsing a string with parentheses-CodePudding

Given the data in the format of the following string:

"(Saturday) March 25 1989"

I need to parse this string and store each element in the corresponding variables. The variable should contain:

day = 25
year = 1989
day = "Saturday"
month = "March"

I have tried to parse the string with the following code but it doesn't seem to work right.

int day, year;
char weekday[20], month[20], dtm[100];

strcpy( dtm, "(Saturday) March 25 1989" );
sscanf( dtm, "(%s[^)] %s %d  %d", weekday, month, &day, &year );

printf("%s %d, %d = %s\n", month, day, year, weekday );

The code has the following output for some reason:

 0, 16 = Saturday)

I'd appreciate any help.

CodePudding user response：

I think the correct format should be this:

sscanf( dtm, " ([^)]) s %d %d", weekday, month, &day, &year );
//            ^  ^     ^   ^
//            |  |     |   limit the number of chars (sizeof month - 1)
//            |  |     the end ) should be matched
//            |  no 's' and limit the number of chars (sizeof weekday - 1)
//            eat whitespaces (like newline)

CodePudding user response：

You're mixing up %s and %[, which are separate specifiers. Furthermore, %[ doesn't eat the stopping character(s) (in this case )), you'll have to do it manually.

With %[, your sscanf call should look like:

sscanf( dtm, "(%[^)]) %s %d  %d", weekday, month, &day, &year );
//                  ^ Eat )
//             ^Scan until )

You'll also want to handle whitespace so that even an input like ( Saturday ) will only scan Saturday:

#define WHITESPACE " \r\n\t\v\f"
sscanf( dtm, " ( %[^)"WHITESPACE"] ) %s %d %d", weekday, month, &day, &year );

And you'll also want to limit the number of characters that should be scanned for a string so you don't suffer a buffer overflow, but Ted's answer already shows how to do this.