Add 'corebinutils/ed/' from commit '93528dc40c12704e0f9ca16475e97e68b4317fb9'

git-subtree-dir: corebinutils/ed
git-subtree-mainline: 0e49ba0e7b8b9bc8bdc61f8c80228252392e758e
git-subtree-split: 93528dc40c12704e0f9ca16475e97e68b4317fb9

1 files changed, 331 insertions, 0 deletions

diff --git a/corebinutils/ed/buf.c b/corebinutils/ed/buf.c
new file mode 100644
index 0000000000..9b41c066ff
--- /dev/null
+++ b/corebinutils/ed/buf.c
@@ -0,0 +1,331 @@
+/* buf.c: This file contains the scratch-file buffer routines for the
+   ed line editor. */
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 1993 Andrew Moore, Talke Studio.
+ * Copyright (c) 2026 Project Tick.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/stat.h>
+
+#include "ed.h"
+
+
+static FILE *sfp;			/* scratch file pointer */
+static off_t sfseek;			/* scratch file position */
+static int seek_write;			/* seek before writing */
+static line_t buffer_head;		/* incore buffer */
+
+/* get_sbuf_line: get a line of text from the scratch file; return pointer
+   to the text */
+char *
+get_sbuf_line(line_t *lp)
+{
+	static char *sfbuf = NULL;	/* buffer */
+	static size_t sfbufsz;		/* buffer size */
+
+	size_t len;
+
+	if (lp == &buffer_head)
+		return NULL;
+	seek_write = 1;				/* force seek on write */
+	/* out of position */
+	if (sfseek != lp->seek) {
+		sfseek = lp->seek;
+		if (fseeko(sfp, sfseek, SEEK_SET) < 0) {
+			fprintf(stderr, "%s\n", strerror(errno));
+			errmsg = "cannot seek temp file";
+			return NULL;
+		}
+	}
+	len = lp->len;
+	REALLOC(sfbuf, sfbufsz, len + 1, NULL);
+	if (fread(sfbuf, sizeof(char), len, sfp) != len) {
+		fprintf(stderr, "%s\n", strerror(errno));
+		errmsg = "cannot read temp file";
+		return NULL;
+	}
+	sfseek += len;				/* update file position */
+	sfbuf[len] = '\0';
+	return sfbuf;
+}
+
+
+/* put_sbuf_line: write a line of text to the scratch file and add a line node
+   to the editor buffer;  return a pointer to the end of the text */
+const char *
+put_sbuf_line(const char *cs)
+{
+	line_t *lp;
+	size_t len;
+	const char *s;
+
+	if ((lp = (line_t *) malloc(sizeof(line_t))) == NULL) {
+		fprintf(stderr, "%s\n", strerror(errno));
+		errmsg = "out of memory";
+		return NULL;
+	}
+	/* assert: cs is '\n' terminated */
+	for (s = cs; *s != '\n'; s++)
+		;
+	if (s - cs >= LINECHARS) {
+		errmsg = "line too long";
+		free(lp);
+		return NULL;
+	}
+	len = s - cs;
+	/* out of position */
+	if (seek_write) {
+		if (fseeko(sfp, (off_t)0, SEEK_END) < 0) {
+			fprintf(stderr, "%s\n", strerror(errno));
+			errmsg = "cannot seek temp file";
+			free(lp);
+			return NULL;
+		}
+		sfseek = ftello(sfp);
+		seek_write = 0;
+	}
+	/* assert: SPL1() */
+	if (fwrite(cs, sizeof(char), len, sfp) != len) {
+		sfseek = -1;
+		fprintf(stderr, "%s\n", strerror(errno));
+		errmsg = "cannot write temp file";
+		free(lp);
+		return NULL;
+	}
+	lp->len = len;
+	lp->seek  = sfseek;
+	add_line_node(lp);
+	sfseek += len;			/* update file position */
+	return ++s;
+}
+
+
+/* add_line_node: add a line node in the editor buffer after the current line */
+void
+add_line_node(line_t *lp)
+{
+	line_t *cp;
+
+	cp = get_addressed_line_node(current_addr);				/* this get_addressed_line_node last! */
+	INSQUE(lp, cp);
+	addr_last++;
+	current_addr++;
+}
+
+
+/* get_line_node_addr: return line number of pointer */
+long
+get_line_node_addr(line_t *lp)
+{
+	line_t *cp = &buffer_head;
+	long n = 0;
+
+	while (cp != lp && (cp = cp->q_forw) != &buffer_head)
+		n++;
+	if (n && cp == &buffer_head) {
+		errmsg = "invalid address";
+		return ERR;
+	 }
+	 return n;
+}
+
+
+/* get_addressed_line_node: return pointer to a line node in the editor buffer */
+line_t *
+get_addressed_line_node(long n)
+{
+	static line_t *lp = &buffer_head;
+	static long on = 0;
+
+	SPL1();
+	if (n > on)
+		if (n <= (on + addr_last) >> 1)
+			for (; on < n; on++)
+				lp = lp->q_forw;
+		else {
+			lp = buffer_head.q_back;
+			for (on = addr_last; on > n; on--)
+				lp = lp->q_back;
+		}
+	else
+		if (n >= on >> 1)
+			for (; on > n; on--)
+				lp = lp->q_back;
+		else {
+			lp = &buffer_head;
+			for (on = 0; on < n; on++)
+				lp = lp->q_forw;
+		}
+	SPL0();
+	return lp;
+}
+
+static char *sfn;				/* scratch file name */
+
+static int
+prepare_scratch_name(void)
+{
+	static const char suffix[] = "ed.XXXXXX";
+	const char *tmpdir;
+	size_t dirlen;
+	size_t suffixlen;
+	size_t need;
+	int needslash;
+	char *path;
+
+	tmpdir = getenv("TMPDIR");
+	if (tmpdir == NULL || tmpdir[0] == '\0')
+		tmpdir = "/tmp";
+	dirlen = strlen(tmpdir);
+	suffixlen = sizeof(suffix);
+	needslash = dirlen > 0 && tmpdir[dirlen - 1] != '/';
+	need = dirlen + (size_t)needslash + suffixlen;
+	if (need > PATH_MAX) {
+		fprintf(stderr, "%s\n", "temporary directory path too long");
+		errmsg = "temporary directory path too long";
+		return ERR;
+	}
+	path = malloc(need);
+	if (path == NULL) {
+		fprintf(stderr, "%s\n", strerror(errno));
+		errmsg = "out of memory";
+		return ERR;
+	}
+	memcpy(path, tmpdir, dirlen);
+	if (needslash)
+		path[dirlen++] = '/';
+	memcpy(path + dirlen, suffix, suffixlen);
+	free(sfn);
+	sfn = path;
+	return 0;
+}
+
+/* open_sbuf: open scratch file */
+int
+open_sbuf(void)
+{
+	int fd = -1;
+	int u;
+
+	isbinary = newline_added = 0;
+	if (prepare_scratch_name() < 0)
+		return ERR;
+	u = umask(077);
+	if ((fd = mkstemp(sfn)) == -1 ||
+	    (sfp = fdopen(fd, "w+")) == NULL) {
+		if (fd != -1) {
+			close(fd);
+			unlink(sfn);
+		}
+		perror(sfn != NULL ? sfn : "mkstemp");
+		errmsg = "cannot open temp file";
+		umask(u);
+		return ERR;
+	}
+	umask(u);
+	return 0;
+}
+
+
+/* close_sbuf: close scratch file */
+int
+close_sbuf(void)
+{
+	if (sfp) {
+		if (fclose(sfp) < 0) {
+			fprintf(stderr, "%s: %s\n", sfn != NULL ? sfn : "ed",
+			    strerror(errno));
+			errmsg = "cannot close temp file";
+			return ERR;
+		}
+		sfp = NULL;
+		if (sfn != NULL)
+			unlink(sfn);
+	}
+	free(sfn);
+	sfn = NULL;
+	sfseek = seek_write = 0;
+	return 0;
+}
+
+
+/* quit: remove_lines scratch file and exit */
+void
+quit(int n)
+{
+	if (sfp) {
+		fclose(sfp);
+		if (sfn != NULL)
+			unlink(sfn);
+	}
+	free(sfn);
+	sfn = NULL;
+	exit(n);
+}
+
+
+static unsigned char ctab[256];		/* character translation table */
+
+/* init_buffers: open scratch buffer; initialize line queue */
+void
+init_buffers(void)
+{
+	int i = 0;
+
+	/* Keep stdin unbuffered to avoid i/o contention with shell escapes
+	   invoked by nonterminal input, e.g.,
+	   ed - <<EOF
+	   !cat
+	   hello, world
+	   EOF */
+	setvbuf(stdin, NULL, _IONBF, 0);
+
+	/* Ensure stdout is line buffered. This avoids bogus delays
+	   of output if stdout is piped through utilities to a terminal. */
+	setvbuf(stdout, NULL, _IOLBF, 0);
+	if (open_sbuf() < 0)
+		quit(2);
+	REQUE(&buffer_head, &buffer_head);
+	for (i = 0; i < 256; i++)
+		ctab[i] = i;
+}
+
+
+/* translit_text: translate characters in a string */
+char *
+translit_text(char *s, int len, int from, int to)
+{
+	static int i = 0;
+
+	unsigned char *us;
+
+	ctab[i] = i;			/* restore table to initial state */
+	ctab[i = from] = to;
+	for (us = (unsigned char *) s; len-- > 0; us++)
+		*us = ctab[*us];
+	return s;
+}