1 files changed, 174 insertions, 0 deletions
diff --git a/util/sbase/unexpand.c b/util/sbase/unexpand.c
new file mode 100644
index 00000000..1818691e
--- /dev/null
+++ b/util/sbase/unexpand.c
@@ -0,0 +1,174 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "utf.h"
+#include "util.h"
+
+static int     aflag      = 0;
+static size_t *tablist    = NULL;
+static size_t  tablistlen = 8;
+
+static size_t
+parselist(const char *s)
+{
+	size_t i;
+	char  *p, *tmp;
+
+	tmp = estrdup(s);
+	for (i = 0; (p = strsep(&tmp, " ,")); i++) {
+		if (*p == '\0')
+			eprintf("empty field in tablist\n");
+		tablist = ereallocarray(tablist, i + 1, sizeof(*tablist));
+		tablist[i] = estrtonum(p, 1, MIN(LLONG_MAX, SIZE_MAX));
+		if (i > 0 && tablist[i - 1] >= tablist[i])
+			eprintf("tablist must be ascending\n");
+	}
+	tablist = ereallocarray(tablist, i + 1, sizeof(*tablist));
+
+	return i;
+}
+
+static void
+unexpandspan(size_t last, size_t col)
+{
+	size_t off, i, j;
+	Rune r;
+
+	if (tablistlen == 1) {
+		i = 0;
+		off = last % tablist[i];
+
+		if ((col - last) + off >= tablist[i] && last < col)
+			last -= off;
+
+		r = '\t';
+		for (; last + tablist[i] <= col; last += tablist[i])
+			efputrune(&r, stdout, "<stdout>");
+		r = ' ';
+		for (; last < col; last++)
+			efputrune(&r, stdout, "<stdout>");
+	} else {
+		for (i = 0; i < tablistlen; i++)
+			if (col < tablist[i])
+				break;
+		for (j = 0; j < tablistlen; j++)
+			if (last < tablist[j])
+				break;
+		r = '\t';
+		for (; j < i; j++) {
+			efputrune(&r, stdout, "<stdout>");
+			last = tablist[j];
+		}
+		r = ' ';
+		for (; last < col; last++)
+			efputrune(&r, stdout, "<stdout>");
+	}
+}
+
+static void
+unexpand(const char *file, FILE *fp)
+{
+	Rune r;
+	size_t last = 0, col = 0, i;
+	int bol = 1;
+
+	while (efgetrune(&r, fp, file)) {
+		switch (r) {
+		case ' ':
+			if (!bol && !aflag)
+				last++;
+			col++;
+			break;
+		case '\t':
+			if (tablistlen == 1) {
+				if (!bol && !aflag)
+					last += tablist[0] - col % tablist[0];
+				col += tablist[0] - col % tablist[0];
+			} else {
+				for (i = 0; i < tablistlen; i++)
+					if (col < tablist[i])
+						break;
+				if (!bol && !aflag)
+					last = tablist[i];
+				col = tablist[i];
+			}
+			break;
+		case '\b':
+			if (bol || aflag)
+				unexpandspan(last, col);
+			col -= (col > 0);
+			last = col;
+			bol = 0;
+			break;
+		case '\n':
+			if (bol || aflag)
+				unexpandspan(last, col);
+			last = col = 0;
+			bol = 1;
+			break;
+		default:
+			if (bol || aflag)
+				unexpandspan(last, col);
+			last = ++col;
+			bol = 0;
+			break;
+		}
+		if ((r != ' ' && r != '\t') || (!aflag && !bol))
+			efputrune(&r, stdout, "<stdout>");
+	}
+	if (last < col && (bol || aflag))
+		unexpandspan(last, col);
+}
+
+static void
+usage(void)
+{
+	eprintf("usage: %s [-a] [-t tablist] [file ...]\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	FILE *fp;
+	int ret = 0;
+	char *tl = "8";
+
+	ARGBEGIN {
+	case 't':
+		tl = EARGF(usage());
+		if (!*tl)
+			eprintf("tablist cannot be empty\n");
+		/* Fallthrough: -t implies -a */
+	case 'a':
+		aflag = 1;
+		break;
+	default:
+		usage();
+	} ARGEND
+
+	tablistlen = parselist(tl);
+
+	if (!argc) {
+		unexpand("<stdin>", stdin);
+	} else {
+		for (; *argv; argc--, argv++) {
+			if (!strcmp(*argv, "-")) {
+				*argv = "<stdin>";
+				fp = stdin;
+			} else if (!(fp = fopen(*argv, "r"))) {
+				weprintf("fopen %s:", *argv);
+				ret = 1;
+				continue;
+			}
+			unexpand(*argv, fp);
+			if (fp != stdin && fshut(fp, *argv))
+				ret = 1;
+		}
+	}
+
+	ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>");
+
+	return ret;
+}