Fixes and checks for seq. Thanks David Galos!

LICENSE

@@ -10,6 +10,7 @@ MIT/X Consortium License
 © 2012 William Haddon <william@haddonthethird.net>
 © 2012 Kurt H. Maier <khm@intma.in>
 © 2012 Christoph Lohmann <20h@r-36.net> 
+© 2012 David Galos <galosd83@students.rowan.edu> 
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the "Software"),

Makefile

@@ -52,6 +52,7 @@ SRC = \
 	tty.c      \
 	uname.c    \
 	seq.c      \
+	seq-test.c \
 	wc.c
 
 OBJ = $(SRC:.c=.o) $(LIB)

seq.c

@@ -5,85 +5,81 @@
 #include <unistd.h>
 #include <stdbool.h>
 #include <libgen.h>
+#include <regex.h>
 
 #include "util.h"
 
-char afmt[4096];
+#define MAX(a, b) (((a) > (b))? (a):(b))
 
-char *
-getalignedwidthfmt(char *fmt, char *starts, char *steps, char *ends)
+int
+validfloat(char *fmt)
 {
-  char starttmp[4096], steptmp[4096], endtmp[4096];
-  char *startdelim, *stepdelim, *enddelim;
-  int startl, startr, stepr, endl, endr;
-  int maxl, maxr;
+	char *end;
 
-  /*
-   * 1.) Get a temp buffer we can work in.
-   * 2.) Calculate the *r(ight) and *l(eft) size.
-   */
-  memmove(starttmp, starts, strlen(starts)+1);
-  startdelim = strchr(starttmp, '.');
-  if (startdelim != NULL) {
-    startdelim[0] = '\0';
-    startr = strlen(startdelim+1);
-  } else {
-    startr = 0;
-  }
-  startl = strlen(starttmp);
-  if (starttmp[0] == '+')
-    startl--;
+	fmt += strspn(fmt, " ");
+	strtod(fmt, &end);
+	if (fmt == end || end != fmt + strlen(fmt))
+		return 0;
 
-  memmove(endtmp, ends, strlen(ends)+1);
-  enddelim = strchr(endtmp, '.');
-  if (enddelim != NULL) {
-    enddelim[0] = '\0';
-    endr = strlen(enddelim+1);
-  } else {
-    endr = 0;
-  }
-  endl = strlen(endtmp);
-  if (endtmp[0] == '+')
-    endl--;
+	return 1;
+}
 
-  /*
-   * We do not care for the left length of the step, because it
-   * will never be displayed.
-   */
-  memmove(steptmp, steps, strlen(steps)+1);
-  stepdelim = strchr(steptmp, '.');
-  if (stepdelim != NULL) {
-    stepdelim[0] = '\0';
-    stepr = strlen(stepdelim+1);
-  } else {
-    stepr = 0;
-  }
+int
+digitsleft(char *d)
+{
+	char *exp;
+	int shift;
 
-  maxl = (startl > endl)? startl : endl;
-  maxr = (startl > endr)? startr : endr;
-  if (stepr > maxr)
-    maxr = stepr;
+	if (d[0] == '-' || d[0] == '+')
+		d++;
+	exp = strpbrk(d, "eE");
+	shift = exp? atoi(exp+1) : 0;
 
-  if (maxl <= 1) {
-    snprintf(afmt, sizeof(afmt), "%%.%df", maxr);
-  } else if (maxr == 0) {
-    snprintf(afmt, sizeof(afmt), "%%0%d.f", maxl);
-  } else {
-    snprintf(afmt, sizeof(afmt), "%%0%d.%df", maxl+maxr+1, maxr);
-  }
+	return MAX(0, strspn(d, "0123456789")+shift);
+}
 
-  return afmt;
+int
+digitsright(char *d)
+{
+	char *exp;
+	int shift, after;
+
+	if (d[0] == '-' || d[0] == '+')
+		d++;
+	exp = strpbrk(d, "eE");
+	shift = exp ? atoi(exp+1) : 0;
+	after = (d = strchr(d, '.'))? strspn(d+1, "0123456789") : 0;
+
+	return MAX(0, after-shift);
+}
+
+int
+validfmt(char *fmt)
+{
+	regex_t reg;
+	int ret;
+
+	regcomp(&reg, "\\([^%]|%%\\)*%[0-9]*\\.[0-9]*[fFgG]"
+			"\\([^%]|%%\\)*", REG_NOSUB);
+	ret = regexec(&reg, fmt, 0, NULL, 0);
+	regfree(&reg);
+
+	return (ret == 0);
 }
 
 int
 main(int argc, char *argv[])
 {
-  char c, *fmt, *sep, *starts, *steps, *ends;
-  bool wflag = false;
+	char c, *fmt, ftmp[4096], *sep, *starts, *steps, *ends;
+	bool wflag, fflag;
 	double start, step, end, out;
+	int left, right;
 
 	sep = "\n";
-  fmt = "%G";
+	fmt = ftmp;
+
+	wflag = false;
+	fflag = false;
 
 	starts = "1";
 	steps = "1";
@@ -92,7 +88,10 @@ main(int argc, char *argv[])
 	while((c = getopt(argc, argv, "f:s:w")) != -1) {
 		switch(c) {
 		case 'f':
+			if (!validfmt(optarg))
+				eprintf("invalid format.\n");
 			fmt = optarg;
+			fflag = true;
 			break;
 		case 's':
 			sep = optarg;
@@ -103,6 +102,9 @@ main(int argc, char *argv[])
 		}
 	}
 
+	if (wflag && fflag)
+		eprintf("-f and -w cannot be combined.\n");
+
 	switch(argc-optind) {
 	case 3:
 		starts = argv[optind++];
@@ -117,10 +119,18 @@ main(int argc, char *argv[])
 		ends = argv[optind++];
 		break;
 	default:
-      eprintf("usage: %s [-w] [-f fmt] [-s separator] [start [step]]"
-		     " end\n", basename(argv[0]));
+		eprintf("usage: %s [-w] [-f fmt] [-s separator] "
+				"[start [step]] end\n",
+				basename(argv[0]));
 	}
 
+	if (!validfloat(starts))
+		eprintf("start is not a valid float.\n");
+	if (!validfloat(steps))
+		eprintf("step is not a valid float.\n");
+	if (!validfloat(ends))
+		eprintf("end is not a valid float.\n");
+
 	start = atof(starts);
 	step = atof(steps);
 	end = atof(ends);
@@ -136,9 +146,18 @@ main(int argc, char *argv[])
 			return EXIT_FAILURE;
 	}
 
-  if (wflag)
-    fmt = getalignedwidthfmt(fmt, starts, steps, ends);
-  printf("%s\n", fmt);
+	right = MAX(digitsright(starts),
+			MAX(digitsright(ends),
+				digitsright(steps)));
+	if (wflag) {
+		left = MAX(digitsleft(starts), digitsleft(ends));
+
+		snprintf(ftmp, sizeof(ftmp), "%%0%d.%df",
+				right+left+(right != 0),
+				right);
+	} else if (fmt == ftmp) {
+		snprintf(ftmp, sizeof(ftmp), "%%.%df", right);
+	}
 
 	for (out = start;;) {
 		printf(fmt, out);