1 /* seq.c - Count from first to last, by increment. 2 * 3 * Copyright 2006 Rob Landley <rob (at) landley.net> 4 * 5 * http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/seq.html 6 7 USE_SEQ(NEWTOY(seq, "<1>3?f:s:w[!fw]", TOYFLAG_USR|TOYFLAG_BIN)) 8 9 config SEQ 10 bool "seq" 11 depends on TOYBOX_FLOAT 12 default y 13 help 14 usage: seq [-w|-f fmt_str] [-s sep_str] [first] [increment] last 15 16 Count from first to last, by increment. Omitted arguments default 17 to 1. Two arguments are used as first and last. Arguments can be 18 negative or floating point. 19 20 -f Use fmt_str as a printf-style floating point format string 21 -s Use sep_str as separator, default is a newline character 22 -w Pad to equal width with leading zeroes 23 */ 24 25 #define FOR_seq 26 #include "toys.h" 27 28 GLOBALS( 29 char *s, *f; 30 31 int precision; 32 ) 33 34 // Ensure there's one %f escape with correct attributes 35 static void insanitize(char *f) 36 { 37 char *s = next_printf(f, 0); 38 39 if (!s) error_exit("bad -f no %%f"); 40 if (-1 == stridx("aAeEfFgG", *s) || (s = next_printf(s, 0))) { 41 // The @ is a byte offset, not utf8 chars. Waiting for somebody to complain. 42 error_exit("bad -f '%s'@%d", f, (int)(s-f+1)); 43 } 44 } 45 46 // Parse a numeric argument setting *prec to the precision of this argument. 47 // This reproduces the "1.234e5" precision bug from upstream. 48 static double parsef(char *s) 49 { 50 char *dp = strchr(s, '.'); 51 52 if (dp++) TT.precision = maxof(TT.precision, strcspn(dp, "eE")); 53 54 return xstrtod(s); 55 } 56 57 void seq_main(void) 58 { 59 double first = 1, increment = 1, last, dd; 60 int i; 61 62 if (!TT.s) TT.s = "\n"; 63 switch (toys.optc) { 64 case 3: increment = parsef(toys.optargs[1]); 65 case 2: first = parsef(*toys.optargs); 66 default: last = parsef(toys.optargs[toys.optc-1]); 67 } 68 69 // Prepare format string with appropriate precision. Can't use %g because 1e6 70 if (toys.optflags & FLAG_f) insanitize(TT.f); 71 else sprintf(TT.f = toybuf, "%%.%df", TT.precision); 72 73 // Pad to largest width 74 if (toys.optflags & FLAG_w) { 75 int len = 0; 76 77 for (i=0; i<3; i++) { 78 dd = (double []){first, increment, last}[i]; 79 len = maxof(len, snprintf(0, 0, TT.f, dd)); 80 } 81 sprintf(TT.f = toybuf, "%%0%d.%df", len, TT.precision); 82 } 83 84 // Other implementations output nothing if increment is 0 and first > last, 85 // but loop forever if first < last or even first == last. We output 86 // nothing for all three, if you want endless output use "yes". 87 if (!increment) return; 88 89 i = 0; 90 for (;;) { 91 // Multiply to avoid accumulating rounding errors from increment. 92 dd = first+i*increment; 93 if ((increment<0 && dd<last) || (increment>0 && dd>last)) break; 94 if (i++) printf("%s", TT.s); 95 printf(TT.f, dd); 96 } 97 98 if (i) printf("\n"); 99 } 100
