Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>

double  min = 1.0;
double  max = 0.0;
double  incr = 1.0;
int     constant = 0;
int     nsteps;
char    *format;

void
usage(void)
{
        fprint(2, "usage: seq [-fformat] [-w] [first [incr]] last\n");
        exits("usage");
}

void
buildfmt(void)
{
        char *dp;
        int w, p, maxw, maxp;
        static char fmt[16];
        char buf[32];
        double val;

        format = "%g\n";
        if(!constant)
                return;
        maxw = 0;
        maxp = 0;
        for(val = min; val <= max; val += incr){
                sprint(buf, "%g", val);
                if(strchr(buf, 'e')!=0)
                        return;
                dp = strchr(buf,'.');
                w = dp==0? strlen(buf): dp-buf;
                p = dp==0? 0: strlen(strchr(buf,'.')+1);
                if(w>maxw)
                        maxw = w;
                if(p>maxp)
                        maxp = p;
        }
        if(maxp > 0)
                maxw += maxp+1;
        sprint(fmt,"%%%d.%df\n", maxw, maxp);
        format = fmt;
}

void
main(int argc, char *argv[]){
        int j, n;
        char buf[256], ffmt[4096];
        double val;

        ARGBEGIN{
        case 'w':
                constant++;
                break;
        case 'f':
                format = EARGF(usage());
                if(format[strlen(format)-1] != '\n'){
                        sprint(ffmt, "%s\n", format);
                        format = ffmt;
                }
                break;
        default:
                goto out;
        }ARGEND
    out:
        if(argc<1 || argc>3)
                usage();
        max = atof(argv[argc-1]);
        if(argc > 1)
                min = atof(argv[0]);
        if(argc > 2)
                incr = atof(argv[1]);
        if(incr == 0){
                fprint(2, "seq: zero increment\n");
                exits("zero increment");
        }
        if(!format)
                buildfmt();
        if(incr > 0){
                for(val = min; val <= max; val += incr){
                        n = sprint(buf, format, val);
                        if(constant)
                                for(j=0; buf[j]==' '; j++)
                                        buf[j] ='0';
                        write(1, buf, n);
                }
        }else{
                for(val = min; val >= max; val += incr){
                        n = sprint(buf, format, val);
                        if(constant)
                                for(j=0; buf[j]==' '; j++)
                                        buf[j] ='0';
                        write(1, buf, n);
                }
        }
        exits(0);
}