strtod

[ygfperson]

double strtod(char*,char**)
i need a replacement, is there a free one? my program cannot use stdlib.h, and the target enviroment is very picky about "standard" functions.
could atof be used to replace this?

[Strider]

What program do you use? If you can't use the stdlib.h file, then you will not be able to use atof() either. Can you use the string.h file? As I remember, the strtod() function is defined in that header.

David

[ygfperson]

i'm writing a graphing calculator for a pda(vtech helio) which uses weird libs. i have the parser for the equation from snippets.org, but it needs strtod. my compiler is gcc, although i don't know what version. the compiler, linker, etc.. are all dos programs. I know i definitely cannot use stdlib.h, but i'm not sure about string.h. i doubt it, though.

[alex]

Can't you use "sscanf" from stdio.h?

alex

[ygfperson]

can't use stdio.h either.

[iain]

why cant you use stdio.h ?

[Salem]

Well a really simple - no error checking - atoi would look like this

char buff[] = "1234";  // for example
int result = 0;
int i;
for ( i = 0 ; buff[i] != '\0' ; i++ ) {
    result = result * 10 + buff[i] - '0';
}

[ygfperson]

the sdk for this pda doesn't include most normal functions. check out the message board at pdabuzz.com -> other platforms -> vtech -> vtech software development for more info. it also sucks at float calculations, although double works.

would i be correct if i said that:
1)strtod(char* sz1,char** psz2) takes the beginning characters of the string sz1 and stopped when it wasn't a number anymore, where that pointer would be passed back through psz2?
2) would i be correct in assuming that the psz2 is not needed most of the time? from eval.c:

if (0.0 == (arg = strtod(str, &endptr)) && .....

endptr appears only twice in eval.c: when it's defined and here. i'm thinking if it's not needed, something like atof could be used instead.