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Shardik Guest
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Compare data |
Posted: Thu Apr 26, 2007 10:30 am |
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I need to compare two ip address, this is my code:
typedef struct {
int v[4];
} ip_addr;
And the problem:
ip_addr ip1=192,168,6,5;
ip_addr ip2=192,168,6,5;
How can i compare this two ip?
ip1==ip2 doesnt work, and ip must be a ip_addr type, what can i do? with pointers? |
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frequentguest Guest
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Posted: Thu Apr 26, 2007 10:59 am |
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A good way to deal with IP addresses is to use a union.
Code: | typedef union
{
int8 bytes[4];
int32 ip
} ip_addr; |
This way you can easily deal with the IP address byte-wise or as a whole.
Code: | ip_addr ip1;
ip1.bytes[0]=255;
ip1.ip=0xFFFFFFFF;
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treitmey
Joined: 23 Jan 2004 Posts: 1094 Location: Appleton,WI USA
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Posted: Thu Apr 26, 2007 11:04 am |
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yup Code: | #include <16F877.h>
#use delay(clock=4000000)
#fuses HS,NOWDT,NOLVP
#use rs232(baud=19200,xmit=PIN_C0,invert,stream=DEBUG,disable_ints) // stderr(same as debug)
#use fast_io (a)
union ip_def
{
int8 oct[4];
int32 combined;
};
union ip_def ip_i;
union ip_def ip_o;
//======================= Main ==============================
void main(void)
{
ip_i.oct[0]=255;
ip_i.oct[1]=255;
ip_i.oct[2]=255;
ip_i.oct[3]=255;
ip_o.oct[0]=255;
ip_o.oct[1]=255;
ip_o.oct[2]=255;
ip_o.oct[3]=1;
tris_a=0xFF;
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
if(ip_i.combined != ip_o.combine) fprintf(DEBUG,"nope\n\r");
while(1)
{
}
}
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Shardik Guest
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Thx |
Posted: Thu Apr 26, 2007 3:41 pm |
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Thxs a lot for the replys, it really help me, but im still having some problems:
Code: |
typedef union{
int8 v[4];
int32 combined;
} ip_addr;
typedef struct {
mac_addr mac;
ip_addr ip;
} arp_table;
arp_table tabla;
ip_addr sr;
tabla.ip=192,168,8,3;
sr=192,168,8,3;
if(tabla.ip.combined==sr.combined) printf(lcd_putc,"YES");
else printf(lcd_putc,"NO");
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Nevers says YES!!! Do you know where is the problem? |
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Shardik Guest
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Posted: Thu Apr 26, 2007 3:48 pm |
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And how can i do with mac address? (6byte addres)
union ip{
int8 v[4];
int32 combined;
}
union mac{
int8 v[6]:
??? combined;
} |
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frequentguest Guest
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Posted: Thu Apr 26, 2007 3:58 pm |
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The purpose of the union is that you can treat the ip address as either a 32-bit int or as 4 individual bytes. I imagine the compiler doesn't know what to do with these lines:
Quote: | Code: | tabla.ip=192,168,8,3;
sr=192,168,8,3; | |
you can use: Code: |
tabla.ip.v[0]=192;
tabla.ip.v[1]=168;
tabla.ip.v[2]=8;
tabla.ip.v[3]=3;
//or easier yet
tabla.ip.combined=0xC0A80803; |
and then do your comparison |
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frequentguest Guest
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Posted: Thu Apr 26, 2007 3:59 pm |
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as for the mac address issue, since the compiler can't handle a 48-bit variable, look at the memcpy() function of the compiler. |
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