1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
#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)
{
int i;
char *dp;
int w, p, maxw, maxp;
static char fmt[16];
char buf[32];
format = "%g\n";
if(!constant)
return;
maxw = 0;
maxp = 0;
for(i=0; i<=nsteps; i++){
sprint(buf, "%g", min+i*incr);
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 i, j, n;
char buf[256], ffmt[4096];
ARGBEGIN{
case 'w':
constant++;
break;
case 'f':
format = ARGF();
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");
}
nsteps = (max-min)/incr+.5;
if(!format)
buildfmt();
for(i=0; i<=nsteps; i++){
n = sprint(buf, format, min+i*incr);
if(constant)
for(j=0; buf[j]==' '; j++)
buf[j] ='0';
write(1, buf, n);
}
exits(0);
}
|