C | compare string format
I want to see if there is any simple parameter for a string equal to the format string. for example, I want this format to .mat[something][something]
equal the usage strcmp
- .mat[r1][r2]
or.mat[4][5]
Is it possible to use sort regular expressions? or something like strcmp(.mat[%s][%s], .mat[r3][r5])
?
By the way, I am using ansi-c Thanks
source to share
Using the closest thing to regex, scan sets scanf
, this would work, but it's surprisingly ugly:
char row[20], col[20], bracket[2], ignored;
if (sscanf(input, ".mat[%19[^]]][%19[^]]%1[]]%c", row, col, bracket, &ignored) == 3) {
// row and col contain the corresponding specifications...
// bracket contains "]"
// %c failed to convert because if the end of string
....
}
Below is the broken down conversion specification for ".mat[r1][r2]"
:
".mat[" // matches .mat[
"%19[^]]" // matches r1 count=1
"][" // matches ][
"%19[^]]" // matches r2 count=2
"%1[]]" // matches ] count=3
"%c" // should not match anything because of the end of string
source to share
An alternative to @chqrlie's excellent answer: this allows different suffixes and notbracket[2]
Use "%n"
that saves scan offset. It will be nonzero if scanning up to this point
// .mat[something][something]
#define PREFIX ".mat"
#define IDX "[%19[^]]]"
#define SUFFIX ""
char r1[20], r2[20];
int n = 0;
sscanf(input, PREFIX INDEX INDEX SUFFIX "%n", r1, r2, &n);
// Reached the end and there was no more
if (n > 0 && input[n] == '\0') Success();
else Failure();
source to share