itoa() and uitoa() in Redlib

lpcware-support — Thu, 31 Mar 2016 20:00:32 GMT

itoa() is non-standard library function which is provided in many other toolchains to convert an integer to a string. To ease porting, the LPCXpresso IDE provides two variants of this function in the Redlib C library....

char * itoa(int value, char *vstring, unsigned int base); 
char * uitoa(unsigned int value, char *vstring, unsigned int base);

which can be accessed via the system header....

#include <stdlib.h>

itoa() converts an integer value to a null-terminated string using the specified base and stores the result in the array pointed to by the vstring parameter. base can take any value between 2 and 16; where 2 = binary, 8 = octal, 10 = decimal and 16 = hexidecimal.

If base is 10 and the value is negative, then the resulting string is preceded with a minus sign (-). With any other base, value is always considered unsigned.

The return value to the function is a pointer to the resulting null-terminated string, the same as parameter vstring.

uitoa() is similar but treats the input value as unsigned in all cases.

Note that the caller is responsible for reserving space for the output character array - the recommended length is 33, which is long enough to contain any possible value regardless of the base used.

Example invocations

    char vstring [33];
    itoa (value,vstring,10); // convert to decimal 
    itoa (value,vstring,16); // convert to hexadecimal
    itoa (value,vstring,8);; // convert to octal

Standards compliance

As noted above, itoa() / uito() are not standard C library functions. A standard-compliant alternative for some cases may be to use sprintf():

     sprintf(vstring,"%d",value); // convert to decimal 
     sprintf(vstring,"%x",value); // convert to hexadecimal 
     sprintf(vstring,"%o",value); // convert to octal

NOTE : The Newlib C library does not provide implementations of itoa() / uitoa().

Re: itoa() and uitoa() in Redlib

manasaads — Wed, 04 Dec 2024 16:06:12 GMT

The itoa() and uitoa() functions are non-standard, but provided in LPCXpresso's Redlib C library for converting integers to strings in different bases (e.g., decimal, hexadecimal, octal). While useful for porting, they are not part of the standard C library. An alternative is using sprintf() for standard compliance. Keep in mind, the caller must allocate sufficient space for the result, typically 33 characters.

topic itoa() and uitoa() in Redlib in LPCXpresso IDE FAQs

itoa() and uitoa() in Redlib

Example invocations

Standards compliance

Re: itoa() and uitoa() in Redlib