How to pass a string as a macro?-CodePudding

There are many functions in the C libraries that require users to input with macros. I wonder, if I have an array of strings, with contents of macros, like so:

char s[][3] = {"SIGINT", "SIGKILL", "SIGSTOP"};

How can I pass these strings as macros? (Like so:)

signal(s[0], do_something);

with do_something is a function pointer.

(and yes, technically I can pass ints in this case, but... hypothetically, ya know?)

EDIT: As @RemyLebeau and SGeorgiades point out, the "SIGINT",... are aliases for integer consts, and therefore can be stored in an int array, like so:

int s[3] = {SIGINT, SIGKILL, SIGSTOP};

CodePudding user response：

Perhaps what you want instead is:

int s[3] = { SIGINT, SIGKILL, SIGSTOP };

signal(s[0], do_something);

CodePudding user response：

Although SGeorgiades and Remy Lebeau already gave you the answer, here is something that I've used in the past to allow conversion and pretty printing of signal numbers and names:

#include <stdio.h>
#include <signal.h>
#include <string.h>

struct sigfun {
    int signo;
    const char *signame;
};

#define SIGFUN(_sig) \
    { \
        .signo = _sig, \
        .signame = #_sig \
    }

struct sigfun siglist[] = {
    SIGFUN(SIGINT),
    SIGFUN(SIGKILL),
    SIGFUN(SIGSTOP),
    // ...
    { .signo = 0, .signame = NULL }
};

#define SIGFORALL(_sig) \
    _sig = siglist;  _sig->signame != NULL;    _sig

int
signame_to_signo(const char *signame)
{
    struct sigfun *sig;

    for (SIGFORALL(sig)) {
        if (strcmp(sig->signame,signame) == 0)
            break;
    }

    return sig->signo;
}

const char *
signo_to_signame(int signo)
{
    struct sigfun *sig;

    for (SIGFORALL(sig)) {
        if (signo == sig->signo)
            break;
    }

    return sig->signame;
}