sh

function ba () {
    echo $(basename "$1")
}

export -f ba
echo "a b/c"|xargs -I @ sh -c "ba '@'"

ba "$@"

#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>

int main(int argc, char *argv[])
{
    int fd = open("a.txt", O_CREAT|O_APPEND|O_WRONLY, 0600);
    if (fd < 0)
        return 1;
    for (int i = 0; i < argc; i++){
        const char *p = argv[i];
        int n = strlen(p);
        write(fd, p, n);
        write(fd, "\n", 1);
    }
    close(fd);
    return 0;
}

#include <unistd.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
    int fd = 0;
    int n = 0;
    char buf[100];
    while ((n = read(fd, buf, sizeof (buf))) > 0) {
        buf[n]=0;
        printf("%s", buf);
    }
    //printf("\n%d\n", n);
    return 0;
}