I have data in the following format \a,b,c,d/ where a,b are strings of letters and numbers; c, d are integers.
I tried using format \%s,%s,%d,%d/ format to scan it, but that causes a,b,c,d/ to be scanf'ed into the first string instead of only a.
Is there something I could type in the format in order to achieve desired result?
You can use the following format string to use commas as delimiters :
"\\%[^,],%[^,],%d,%d/"
The idea is to tell scanf to read anything that isn't a comma for each string, then read the delimiting comma and continue.
Here is a (bad and unsafe!) example:
char a[100], b[100];
int c=0, d=0;
scanf("\\%[^','],%[^','],%d,%d/", a, b, &c, &d);
printf("%s, %s, %d, %d\n", a, b, c, d);
In real code, you'll want to write something safer. You can for example use fgets to read a full line of input then reuse the same format string with sscanf to parse it.
Read carefully the documentation of fscanf(3).
You might try something like
char str1[80];
char str2[80];
memset (str1, 0, sizeof(str1));
memset (str2, 0, sizeof(str2));
int n3 = 0, n4 = 0;
int pos = -1;
if (scanf ("\\ %79[A-Za-z0-9], %79[A-Za-z0-9], %d, %d /%n",
str1, str2, &n3, &n4, &pos) >= 4
&& pos > 0) {
// be happy with your input
}
else {
// input failure
}
That won't work if you have a wider notion of letters, like French é or Russian Ы ; both are single letters existing in UTF-8 but represented in several bytes.
I added some spaces (mostly for readability) in the format string (but scanf is often skipping spaces anyway, e.g. for %d). If you don't accept spaces -like an input line such as \AB3T, C54x, 234, 65/ , read each line with getline(3) or fgets(3) and parse it manually (perhaps with the help of sscanf and strtol ...). Notice that %d is skipping spaces! I also am clearing the variables to get more deterministic behavior. Notice that %n gives you the amount of read characters (actually, bytes!) and that scanf returns the number of scanned items.
My straightforward solution:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main()
{
char a[10010];
gets(a);
int l = strlen(a);
char storded_first[10010], storded_second[10010];
char for_int_c[10010], for_int_d[10010];
int c,d;
char first_symbol, last_symbol;
int i;
int cnt = 0;
int j=0;
for(i=0; i<l; i++)
{
if(a[i]=='\\')
first_symbol = a[i];
else if(a[i]=='/')
last_symbol = a[i];
else if(a[i]==',')
{
cnt++;
j=0;
}
else if(cnt==0)
{
storded_first[j]=a[i];
j++;
}
else if(cnt==1)
{
storded_second[j]=a[i];
j++;
}
else if(cnt==2)
{
for_int_c[j]=a[i];
j++;
}
else if(cnt==3)
{
for_int_d[j]=a[i];
j++;
}
}
c = atoi(for_int_c);
d = atoi(for_int_d);
printf("%c%s, %s, %d, %d%c\n",first_symbol, storded_first, storded_second, c, d, last_symbol);
return 0;
}