1/* See LICENSE file for copyright and license details. */
2
3
4#include <stdio.h>
5#include <stdlib.h>
6#include <string.h>
7
8#include "util.h"
9
10static int
11digitsleft(const char *d)
12{
13 int shift;
14 const char *exp;
15
16 if (*d == '+')
17 d++;
18 exp = strpbrk(d, "eE");
19 shift = exp ? estrtonum(exp + 1, INT_MIN, INT_MAX) : 0;
20
21 return MAX(0, (int)strspn(d, "-0123456789") + shift);
22}
23
24static int
25digitsright(const char *d)
26{
27 int shift, after;
28 const char *exp;
29
30 exp = strpbrk(d, "eE");
31 shift = exp ? estrtonum(&exp[1], INT_MIN, INT_MAX) : 0;
32 after = (d = strchr(d, '.')) ? strspn(&d[1], "0123456789") : 0;
33
34 return MAX(0, after - shift);
35}
36
37static int
38validfmt(const char *fmt)
39{
40 int occur = 0;
41
42literal:
43 while (*fmt)
44 if (*fmt++ == '%')
45 goto format;
46 return occur == 1;
47
48format:
49 if (*fmt == '%') {
50 fmt++;
51 goto literal;
52 }
53 fmt += strspn(fmt, "-+#0 '");
54 fmt += strspn(fmt, "0123456789");
55 if (*fmt == '.') {
56 fmt++;
57 fmt += strspn(fmt, "0123456789");
58 }
59 if (*fmt == 'L')
60 fmt++;
61
62 switch (*fmt) {
63 // ?man -f: force the operation
64 case 'f': case 'F':
65 case 'g': case 'G':
66 case 'e': case 'E':
67 case 'a': case 'A':
68 occur++;
69 goto literal;
70 default:
71 return 0;
72 }
73}
74
75static void
76usage(void)
77{
78 eprintf("usage: %s [-f fmt] [-s sep] [-w] "
79 "[startnum [step]] endnum\n", argv0);
80}
81
82// ?man seq: print sequence of numbers
83// ?man print a sequence of numbers from start to end
84int
85main(int argc, char *argv[])
86{
87 double start, step, end, out, dir;
88 int wflag = 0, left, right;
89 char *tmp, ftmp[BUFSIZ], *fmt = ftmp;
90 const char *starts = "1", *steps = "1", *ends = "1", *sep = "\n";
91
92 ARGBEGIN {
93 // ?man -f:str: force the operation
94 case 'f':
95 if (!validfmt(tmp=EARGF(usage())))
96 eprintf("%s: invalid format\n", tmp);
97 fmt = tmp;
98 break;
99 // ?man -s:str: silent mode or print summary
100 case 's':
101 sep = EARGF(usage());
102 break;
103 // ?man -w: wait for completion
104 case 'w':
105 wflag = 1;
106 break;
107 default:
108 usage();
109 } ARGEND
110
111 switch (argc) {
112 case 3:
113 steps = argv[1];
114 argv[1] = argv[2];
115 /* fallthrough */
116 case 2:
117 starts = argv[0];
118 argv++;
119 /* fallthrough */
120 case 1:
121 ends = argv[0];
122 break;
123 default:
124 usage();
125 }
126 start = estrtod(starts);
127 step = estrtod(steps);
128 end = estrtod(ends);
129
130 dir = (step > 0) ? 1.0 : -1.0;
131 if (step == 0 || start * dir > end * dir)
132 return 1;
133
134 if (fmt == ftmp) {
135 right = MAX(digitsright(starts),
136 MAX(digitsright(ends),
137 digitsright(steps)));
138
139 if (wflag) {
140 left = MAX(digitsleft(starts), digitsleft(ends));
141
142 snprintf(ftmp, sizeof ftmp, "%%0%d.%df",
143 right + left + (right != 0), right);
144 } else
145 snprintf(ftmp, sizeof ftmp, "%%.%df", right);
146 }
147 for (out = start; out * dir <= end * dir; out += step) {
148 if (out != start)
149 fputs(sep, stdout);
150 printf(fmt, out);
151 }
152 putchar('\n');
153
154 return fshut(stdout, "<stdout>");
155}
