1 #include <u.h>
2 #include <libc.h>
3
4 double min = 1.0;
5 double max = 0.0;
6 double incr = 1.0;
7 int constant = 0;
8 int nsteps;
9 char *format;
10
11 void
usage(void)12 usage(void)
13 {
14 fprint(2, "usage: seq [-fformat] [-w] [first [incr]] last\n");
15 exits("usage");
16 }
17
18 void
buildfmt(void)19 buildfmt(void)
20 {
21 char *dp;
22 int w, p, maxw, maxp;
23 static char fmt[16];
24 char buf[32];
25 double val;
26
27 format = "%g\n";
28 if(!constant)
29 return;
30 maxw = 0;
31 maxp = 0;
32 for(val = min; val <= max; val += incr){
33 sprint(buf, "%g", val);
34 if(strchr(buf, 'e')!=0)
35 return;
36 dp = strchr(buf,'.');
37 w = dp==0? strlen(buf): dp-buf;
38 p = dp==0? 0: strlen(strchr(buf,'.')+1);
39 if(w>maxw)
40 maxw = w;
41 if(p>maxp)
42 maxp = p;
43 }
44 if(maxp > 0)
45 maxw += maxp+1;
46 sprint(fmt,"%%%d.%df\n", maxw, maxp);
47 format = fmt;
48 }
49
50 void
main(int argc,char * argv[])51 main(int argc, char *argv[]){
52 int j, n;
53 char buf[256], ffmt[4096];
54 double val;
55
56 ARGBEGIN{
57 case 'w':
58 constant++;
59 break;
60 case 'f':
61 format = EARGF(usage());
62 if(format[strlen(format)-1] != '\n'){
63 sprint(ffmt, "%s\n", format);
64 format = ffmt;
65 }
66 break;
67 default:
68 goto out;
69 }ARGEND
70 out:
71 if(argc<1 || argc>3)
72 usage();
73 max = atof(argv[argc-1]);
74 if(argc > 1)
75 min = atof(argv[0]);
76 if(argc > 2)
77 incr = atof(argv[1]);
78 if(incr == 0){
79 fprint(2, "seq: zero increment\n");
80 exits("zero increment");
81 }
82 if(!format)
83 buildfmt();
84 if(incr > 0){
85 for(val = min; val <= max; val += incr){
86 n = sprint(buf, format, val);
87 if(constant)
88 for(j=0; buf[j]==' '; j++)
89 buf[j] ='0';
90 write(1, buf, n);
91 }
92 }else{
93 for(val = min; val >= max; val += incr){
94 n = sprint(buf, format, val);
95 if(constant)
96 for(j=0; buf[j]==' '; j++)
97 buf[j] ='0';
98 write(1, buf, n);
99 }
100 }
101 exits(0);
102 }
103