Check getline()-return-values properly

It's not useful when 0 is returned anyway, so be sure that we have a
string with length > 0, this also solves some indexing-gotchas like
"len - 1" and so on.
Also, add checked getline()'s whenever it has been forgotten and
clean up the error-messages.

comm.c

@@ -62,7 +62,7 @@ main(int argc, char *argv[])
 		for (i = 0; i < 2; i++) {
 			if (diff && i == (diff < 0))
 				continue;
-			if (getline(&line[i], &linelen[i], fp[i]) >= 0)
+			if (getline(&line[i], &linelen[i], fp[i]) > 0)
 				continue;
 			if (ferror(fp[i]))
 				eprintf("getline %s:", argv[i]);

cron.c

@@ -304,7 +304,7 @@ loadentries(void)
 		return -1;
 	}
 
-	for (y = 0; (len = getline(&line, &size, fp)) != -1; y++) {
+	for (y = 0; (len = getline(&line, &size, fp)) > 0; y++) {
 		p = line;
 		if (line[0] == '#' || line[0] == '\n' || line[0] == '\0')
 			continue;

cut.c

@@ -114,7 +114,7 @@ cut(FILE *fp, char *fname)
 	ssize_t len;
 	Range *r;
 
-	while ((len = getline(&buf, &size, fp)) >= 0) {
+	while ((len = getline(&buf, &size, fp)) > 0) {
 		if (len && buf[len - 1] == '\n')
 			buf[len - 1] = '\0';
 		if (mode == 'f' && !utfutf(buf, delim)) {

fold.c

@@ -55,7 +55,7 @@ fold(FILE *fp, const char *fname)
 	char *buf = NULL;
 	size_t size = 0;
 
-	while (getline(&buf, &size, fp) >= 0)
+	while (getline(&buf, &size, fp) > 0)
 		foldline(buf);
 	if (ferror(fp))
 		eprintf("getline %s:", fname);

grep.c

@@ -87,7 +87,7 @@ addpatternfile(FILE *fp)
 	static size_t size = 0;
 	ssize_t len = 0;
 
-	while ((len = getline(&buf, &size, fp)) != -1) {
+	while ((len = getline(&buf, &size, fp)) > 0) {
 		if (len > 0 && buf[len - 1] == '\n')
 			buf[len - 1] = '\0';
 		addpattern(buf);
@@ -106,7 +106,7 @@ grep(FILE *fp, const char *str)
 	struct pattern *pnode;
 	int match = NoMatch;
 
-	for (n = 1; (len = getline(&buf, &size, fp)) != -1; n++) {
+	for (n = 1; (len = getline(&buf, &size, fp)) > 0; n++) {
 		/* Remove the trailing newline if one is present. */
 		if (len && buf[len - 1] == '\n')
 			buf[len - 1] = '\0';

head.c

@@ -12,7 +12,7 @@ head(FILE *fp, const char *fname, size_t n)
 	size_t i = 0, size = 0;
 	ssize_t len;
 
-	while (i < n && (len = getline(&buf, &size, fp)) >= 0) {
+	while (i < n && (len = getline(&buf, &size, fp)) > 0) {
 		fputs(buf, stdout);
 		i += (len && (buf[len - 1] == '\n'));
 	}

libutil/crypt.c

@@ -45,7 +45,7 @@ mdchecklist(FILE *listfp, struct crypt_ops *ops, uint8_t *md, size_t sz,
 	int r;
 	char *line = NULL, *file, *p;
 
-	while (getline(&line, &bufsiz, listfp) != -1) {
+	while (getline(&line, &bufsiz, listfp) > 0) {
 		if (!(file = strstr(line, "  "))) {
 			(*formatsucks)++;
 			continue;

libutil/getlines.c

@@ -13,7 +13,7 @@ getlines(FILE *fp, struct linebuf *b)
 	size_t size = 0, linelen;
 	ssize_t len;
 
-	while ((len = getline(&line, &size, fp)) != -1) {
+	while ((len = getline(&line, &size, fp)) > 0) {
 		if (++b->nlines > b->capacity) {
 			b->capacity += 512;
 			nline = erealloc(b->lines, b->capacity * sizeof(*b->lines));

logger.c

@@ -70,7 +70,7 @@ main(int argc, char *argv[])
 	openlog(tag ? tag : getlogin(), logflags, 0);
 
 	if (!argc) {
-		while (getline(&buf, &sz, stdin) >= 0)
+		while (getline(&buf, &sz, stdin) > 0)
 			syslog(priority, "%s", buf);
 		if (ferror(stdin))
 			eprintf("getline %s:", "<stdin>");

nl.c

@@ -50,7 +50,7 @@ nl(const char *fname, FILE *fp)
 	int donumber, oldsection, section = 1, bl = 1;
 	char *buf = NULL;
 
-	while (getline(&buf, &size, fp) >= 0) {
+	while (getline(&buf, &size, fp) > 0) {
 		donumber = 0;
 		oldsection = section;
 

sed.c

@@ -451,7 +451,7 @@ read_line(FILE *f, String *s)
 
 	if ((len = getline(&s->str, &s->cap, f)) < 0) {
 		if (ferror(f))
-			eprintf("getline failed\n");
+			eprintf("getline:");
 		return EOF;
 	}
 	if (s->str[--len] == '\n')

sort.c

@@ -63,9 +63,9 @@ check(FILE *fp)
 {
 	static struct { char *buf; size_t size; } prev, cur, tmp;
 
-	if (!prev.buf)
+	if (!prev.buf && getline(&prev.buf, &prev.size, fp) < 0)
-		getline(&prev.buf, &prev.size, fp);
+		eprintf("getline:");
-	while (getline(&cur.buf, &cur.size, fp) != -1) {
+	while (getline(&cur.buf, &cur.size, fp) > 0) {
 		if (uflag > linecmp((const char **) &cur.buf, (const char **) &prev.buf)) {
 			if (!Cflag)
 				weprintf("disorder: %s", cur.buf);

tail.c

@@ -24,7 +24,7 @@ dropinit(FILE *fp, const char *str)
 	ssize_t len;
 
 	if (mode == 'n') {
-		while (i < num && (len = getline(&buf, &size, fp)) >= 0)
+		while (i < num && (len = getline(&buf, &size, fp)) > 0)
 			if (len > 0 && buf[len - 1] == '\n')
 				i++;
 	} else {
@@ -46,7 +46,7 @@ taketail(FILE *fp, const char *str)
 		ring = ecalloc(num, sizeof *ring);
 		size = ecalloc(num, sizeof *size);
 
-		for (i = j = 0; getline(&ring[i], &size[i], fp) != -1; )
+		for (i = j = 0; getline(&ring[i], &size[i], fp) > 0; )
 			i = j = (i + 1) % num;
 	} else {
 		r = ecalloc(num, sizeof *r);
@@ -131,7 +131,7 @@ main(int argc, char *argv[])
 				continue;
 			}
 			for (tmp = NULL, tmpsize = 0;;) {
-				while (getline(&tmp, &tmpsize, fp) >= 0) {
+				while (getline(&tmp, &tmpsize, fp) > 0) {
 					fputs(tmp, stdout);
 					fflush(stdout);
 				}

uniq.c

@@ -76,7 +76,7 @@ uniq(FILE *fp, FILE *ofp)
 	size_t size = 0;
 	ssize_t len;
 
-	while ((len = getline(&buf, &size, fp)) >= 0)
+	while ((len = getline(&buf, &size, fp)) > 0)
 		uniqline(ofp, buf, (size_t)len);
 }
 

uudecode.c

@@ -166,7 +166,7 @@ uudecode(FILE *fp, FILE *outfp)
 #define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) )
 #define OUT_OF_RANGE(c) eprintf("character %c out of range: [%d-%d]\n", (c), 1 + ' ', 077 + ' ' + 1)
 
-	while ((len = getline(&bufb, &n, fp)) != -1) {
+	while ((len = getline(&bufb, &n, fp)) > 0) {
 		p = bufb;
 		/* trim newlines */
 		if (!len || bufb[len - 1] != '\n')
@@ -210,7 +210,8 @@ uudecode(FILE *fp, FILE *outfp)
 			eprintf("read error:");
 	}
 	/* check for end or fail */
-	len = getline(&bufb, &n, fp);
+	if ((len = getline(&bufb, &n, fp)) < 0)
+		eprintf("getline:");
 	if (len < 3 || strncmp(bufb, "end", 3) || bufb[3] != '\n')
 		eprintf("invalid uudecode footer \"end\" not found\n");
 	free(bufb);