git: b05785953e55 - main - cut: use getline() instead of fgetln()

The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=b05785953e555e3dd13a162a8854076212026ca5

commit b05785953e555e3dd13a162a8854076212026ca5
Author:     Martin Tournoij <martin@arp242.net>
AuthorDate: 2024-04-19 21:11:30 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2024-04-19 21:52:21 +0000

    cut: use getline() instead of fgetln()
    
    This replaces fgetln() with getline(). The main reason for this is
    portability, making things easier for people who want to compile these
    tools on non-FreeBSD systems.
    
    I appreciate that's probably not the top concern for FreeBSD base tools,
    but fgetln() is impossible to port to most platforms, as concurrent
    access is essentially impossible to implement fully correct without the
    line buffer on the FILE struct. Other than this, many generic FreeBSD
    tools compile fairly cleanly on Linux with a few small changes.
    
    Most uses of fgetln() pre-date getline() support (added in 2009 with
    69099ba2ec8b), and there's been some previous patches (ee3ca711a898
    8c98e6b1a7f3 1a2a4fc8ce1b) for other tools.
    
    Obtained from:  https://github.com/dcantrell/bsdutils and
                    https://github.com/chimera-linux/chimerautils
    Signed-off-by: Martin Tournoij <martin@arp242.net>
    Reviewed by: imp
    Pull Request: https://github.com/freebsd/freebsd-src/pull/893
---
 usr.bin/cut/cut.c | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/usr.bin/cut/cut.c b/usr.bin/cut/cut.c
index df4a2d7eb132..60ff5a31062a 100644
--- a/usr.bin/cut/cut.c
+++ b/usr.bin/cut/cut.c
@@ -268,14 +268,15 @@ b_cut(FILE *fp, const char *fname __unused)
 static int
 b_n_cut(FILE *fp, const char *fname)
 {
-	size_t col, i, lbuflen;
-	char *lbuf;
+	size_t col, i, bufsize = 0;
+	ssize_t lbuflen;
+	char *lbuf = NULL;
 	int canwrite, clen, warned;
 	mbstate_t mbs;
 
 	memset(&mbs, 0, sizeof(mbs));
 	warned = 0;
-	while ((lbuf = fgetln(fp, &lbuflen)) != NULL) {
+	while ((lbuflen = getline(&lbuf, &bufsize, fp)) >= 0) {
 		for (col = 0; lbuflen > 0; col += clen) {
 			if ((clen = mbrlen(lbuf, lbuflen, &mbs)) < 0) {
 				if (!warned) {
@@ -324,6 +325,7 @@ b_n_cut(FILE *fp, const char *fname)
 		if (lbuflen > 0)
 			putchar('\n');
 	}
+	free(lbuf);
 	return (warned);
 }
 
@@ -382,21 +384,22 @@ f_cut(FILE *fp, const char *fname)
 	int field, i, isdelim;
 	char *pos, *p;
 	int output;
-	char *lbuf, *mlbuf;
-	size_t clen, lbuflen, reallen;
+	char *lbuf = NULL;
+	size_t clen, bufsize = 0, reallen;
+	ssize_t lbuflen;
 
-	mlbuf = NULL;
-	while ((lbuf = fgetln(fp, &lbuflen)) != NULL) {
+	while ((lbuflen = getline(&lbuf, &bufsize, fp)) >= 0) {
 		reallen = lbuflen;
 		/* Assert EOL has a newline. */
-		if (*(lbuf + lbuflen - 1) != '\n') {
+		if (lbuflen > 0 && *(lbuf + lbuflen - 1) != '\n') {
 			/* Can't have > 1 line with no trailing newline. */
-			mlbuf = malloc(lbuflen + 1);
-			if (mlbuf == NULL)
-				err(1, "malloc");
-			memcpy(mlbuf, lbuf, lbuflen);
-			*(mlbuf + lbuflen) = '\n';
-			lbuf = mlbuf;
+			if ((ssize_t)bufsize < (lbuflen + 1)) {
+				bufsize = lbuflen + 1;
+				lbuf = realloc(lbuf, bufsize);
+			}
+			if (lbuf == NULL)
+				err(1, "realloc");
+			lbuf[lbuflen] = '\n';
 			reallen++;
 		}
 		output = 0;
@@ -404,7 +407,7 @@ f_cut(FILE *fp, const char *fname)
 			clen = mbrtowc(&ch, p, lbuf + reallen - p, NULL);
 			if (clen == (size_t)-1 || clen == (size_t)-2) {
 				warnc(EILSEQ, "%s", fname);
-				free(mlbuf);
+				free(lbuf);
 				return (1);
 			}
 			if (clen == 0)
@@ -431,7 +434,7 @@ f_cut(FILE *fp, const char *fname)
 				    NULL);
 				if (clen == (size_t)-1 || clen == (size_t)-2) {
 					warnc(EILSEQ, "%s", fname);
-					free(mlbuf);
+					free(lbuf);
 					return (1);
 				}
 				if (clen == 0)
@@ -463,7 +466,7 @@ f_cut(FILE *fp, const char *fname)
 		}
 		(void)putchar('\n');
 	}
-	free(mlbuf);
+	free(lbuf);
 	return (0);
 }