I write a program which takes IP address as an argument and i wanted to store this IP address in the unit32_t. I can easily convert uint32_t to back to character array. How to convert IP address in Char Array to uint32_t.
For example
./IPtoCHAR 1079733050
uint32_t to IP Address => 64.91.107.58
But how to write a program that does the reverse task?
./CHARtoIP 64.91.107.58
for the first IPtoCHAR, it is
unsigned int ipAddress = atoi(argv[1]);
printf("IP Address %d.%d.%d.%d \\n",((ipAddress >> 24) & 0xFF),((ipAddress >> 16) & 0xFF),((ipAddress >> 8) & 0xFF),(ipAddress & 0xFF));
But all these below does not work
uint32_t aa=(uint32_t)("64.91.107.58");
uint32_t aa=atoi("64.91.107.58");
uint32_t aa=strtol("64.91.107.58",NULL,10);
In case you don't have access to inet_* functions or need to code this yourself due to any other strange reason, you can use a function like this:
#include <stdio.h>
/**
* Convert human readable IPv4 address to UINT32
* @param pDottedQuad Input C string e.g. "192.168.0.1"
* @param pIpAddr Output IP address as UINT32
* return 1 on success, else 0
*/
int ipStringToNumber (const char* pDottedQuad,
unsigned int * pIpAddr)
{
unsigned int byte3;
unsigned int byte2;
unsigned int byte1;
unsigned int byte0;
char dummyString[2];
/* The dummy string with specifier %1s searches for a non-whitespace char
* after the last number. If it is found, the result of sscanf will be 5
* instead of 4, indicating an erroneous format of the ip-address.
*/
if (sscanf (pDottedQuad, "%u.%u.%u.%u%1s",
&byte3, &byte2, &byte1, &byte0, dummyString) == 4)
{
if ( (byte3 < 256)
&& (byte2 < 256)
&& (byte1 < 256)
&& (byte0 < 256)
)
{
*pIpAddr = (byte3 << 24)
+ (byte2 << 16)
+ (byte1 << 8)
+ byte0;
return 1;
}
}
return 0;
}
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