How do I split a string once?
I want to split a string into only two parts at the first space character. For exampl开发者_如何学Ce, I have a string "Hay Guys LOL" and when split, "Hay" should be in one variable, and "Guys LOL" in the other.
I have looked into functions like strtok
- it works, but I would prefer not looping and then combining the strings.
Here is what I currently have (trying sscanf):
char test[32];
strcpy(test, "Hay Guys LOL\r\n");
// p1 should have "Hay", and p2 have "Guys LOL"?
char p1[16], p2[16];
sscanf(test, "%s %s\r\n", p1, p2);
printf("p1: %s\n", p1);
printf("p2: %s\n", p2);
Thanks!
Make it:
sscanf(test, "%s %[^\r\n]", p1, p2);
The first %s
will only read the first string upto the first blankspace read "Hay". Next the scanset will read until a '\r'
or '\n'
is not found in the string (^
in the []
inverts the set) . Therefore the %[^\r\n]
will read the rest of the string into p2
.
UPDATE
As @Adam Rosenfield told, to avoid buffer overflows you need to limit the numbers of characters put into p1
and p2
by sscanf
. You specify the nos of characters like %10[^\r\n]
and %10s
. Because these numbers needs to be a part of the format string therefore you might want to make the format string dynamically before use.
char format_string[MAX];
sprintf (format_string, "%%%ds %%%d[^\\r\\n]", 10, 10);
sscanf (test, format_string, p1, p2);
Above the format string with the length limitation is made first and then it is used. Note the escape characters. %%
is used to print a single %
in the output and \\
is used to print a single \
in the output string.
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