Date: Wed, 30 Jan 2002 20:16:15 +1100 From: "Tim J. Robbins" <tim@robbins.dropbear.id.au> To: freebsd-standards@FreeBSD.ORG Subject: fold -b and -s options patch Message-ID: <20020130201615.A9151@descent.robbins.dropbear.id.au>
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This patch adds the -b and -s options to fold. It's mostly taken from
NetBSD but I've hopefully kept it compilable by K&R compilers.
Tim
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Index: fold/fold.1
===================================================================
RCS file: /home/ncvs/src/usr.bin/fold/fold.1,v
retrieving revision 1.7
diff -u -r1.7 fold.1
--- fold/fold.1 2001/12/12 18:25:53 1.7
+++ fold/fold.1 2002/01/30 09:16:34
@@ -40,6 +40,7 @@
.Nd "fold long lines for finite width output device"
.Sh SYNOPSIS
.Nm
+.Op Fl bs
.Op Fl w Ar width
.Op Ar
.Sh DESCRIPTION
@@ -50,6 +51,14 @@
.Pp
The following option is available:
.Bl -tag -width indent
+.It Fl b
+Count
+.Ar width
+in bytes rather than column positions.
+.It Fl s
+Fold line after the last blank character within the first
+.Ar width
+column positions (or bytes).
.It Fl w Ar width
Specify a line width to use instead of the default 80 characters.
.Ar Width
Index: fold/fold.c
===================================================================
RCS file: /home/ncvs/src/usr.bin/fold/fold.c,v
retrieving revision 1.6
diff -u -r1.6 fold.c
--- fold/fold.c 2001/12/12 18:25:53 1.6
+++ fold/fold.c 2002/01/30 09:16:35
@@ -52,13 +52,19 @@
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
#include <unistd.h>
#define DEFLINEWIDTH 80
void fold __P((int));
+static int new_column_position __P((int, int));
static void usage __P((void));
+int count_bytes = 0;
+int split_words = 0;
+
int
main(argc, argv)
int argc;
@@ -69,8 +75,14 @@
char *p;
width = -1;
- while ((ch = getopt(argc, argv, "0123456789w:")) != -1)
+ while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1)
switch (ch) {
+ case 'b':
+ count_bytes = 1;
+ break;
+ case 's':
+ split_words = 1;
+ break;
case 'w':
if ((width = atoi(optarg)) <= 0) {
errx(1, "illegal width value");
@@ -98,7 +110,7 @@
fold(width);
else for (; *argv; ++argv)
if (!freopen(*argv, "r", stdin)) {
- err(1, "%s", *argv);
+ err(EX_NOINPUT, "%s", *argv);
} else
fold(width);
exit(0);
@@ -107,57 +119,115 @@
static void
usage()
{
- (void)fprintf(stderr, "usage: fold [-w width] [file ...]\n");
+ (void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n");
exit(1);
}
+/*
+ * Fold the contents of standard input to fit within WIDTH columns
+ * (or bytes) and write to standard output.
+ *
+ * If split_words is set, split the line at the last space character
+ * on the line. This flag necessitates storing the line in a buffer
+ * until the current column > width, or a newline or EOF is read.
+ *
+ * The buffer can grow larger than WIDTH due to backspaces and carriage
+ * returns embedded in the input stream.
+ */
void
fold(width)
register int width;
{
- register int ch, col, new;
-
- for (col = 0;;) {
- switch (ch = getchar()) {
- case EOF:
- return;
- case '\b':
- new = col ? col - 1 : 0;
- break;
- case '\n':
- case '\r':
- new = 0;
- break;
- case '\t':
- new = (col + 8) & ~7;
- break;
- default:
- new = col + 1;
- break;
+ static char *buf = NULL;
+ static int buf_max = 0;
+ register int ch, col;
+ int indx;
+
+ col = indx = 0;
+ while ((ch = getchar()) != EOF) {
+ if (ch == '\n') {
+ if (indx != 0)
+ fwrite (buf, 1, indx, stdout);
+ putchar('\n');
+ col = indx = 0;
+ continue;
}
+
+ col = new_column_position (col, ch);
+ if (col > width) {
+ int i, last_space;
+
+#ifdef __GNUC__
+ last_space = 0; /* XXX gcc */
+#endif
+ if (split_words) {
+ for (i = 0, last_space = -1; i < indx; i++)
+ if (buf[i] == ' ')
+ last_space = i;
+ }
+
+ if (split_words && last_space != -1) {
+ last_space++;
- if (new > width) {
+ fwrite (buf, 1, last_space, stdout);
+ memmove (buf, buf+last_space, indx-last_space);
+
+ indx -= last_space;
+ col = 0;
+ for (i = 0; i < indx; i++) {
+ col = new_column_position (col, buf[i]);
+ }
+ } else {
+ fwrite (buf, 1, indx, stdout);
+ col = indx = 0;
+ }
putchar('\n');
- col = 0;
+
+ /* calculate the column position for the next line. */
+ col = new_column_position (col, ch);
+ }
+
+ if (indx + 1 > buf_max) {
+ /* Allocate buffer in LINE_MAX increments */
+ buf_max += 2048;
+ if((buf = realloc (buf, buf_max)) == NULL) {
+ err (1, "realloc");
+ /* NOTREACHED */
+ }
}
- putchar(ch);
+ buf[indx++] = ch;
+ }
+ if (indx != 0)
+ fwrite (buf, 1, indx, stdout);
+}
+
+/*
+ * calculate the column position
+ */
+static int
+new_column_position (col, ch)
+ int col, ch;
+{
+ if (!count_bytes) {
switch (ch) {
case '\b':
if (col > 0)
--col;
break;
- case '\n':
case '\r':
col = 0;
break;
case '\t':
- col += 8;
- col &= ~7;
+ col = (col + 8) & ~7;
break;
default:
++col;
break;
}
+ } else {
+ ++col;
}
+
+ return col;
}
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