Display an error message for "sed -i" if the file is unwritable

Previously, sed would fail silently if it was unable to move the
temporary file into place.  Also allow "sed -i" on symbolic link--the
link will be broken but this matches GNU sed behavior.  From espie@
OK op@

diff --git a/usr.bin/sed/main.c b/usr.bin/sed/main.c
index 0d741db..979cac6 100644 (file)
--- a/usr.bin/sed/main.c
+++ b/usr.bin/sed/main.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: main.c,v 1.45 2024/06/18 00:32:22 millert Exp $       */
+/*     $OpenBSD: main.c,v 1.46 2024/07/17 03:05:19 millert Exp $       */
 
 /*-
  * Copyright (c) 1992 Diomidis Spinellis.
@@ -310,7 +310,7 @@ finish_file(void)
                fclose(infile);
                if (*oldfname != '\0') {
                        if (rename(fname, oldfname) != 0) {
-                               warning("rename()");
+                               warning("rename(): %s", strerror(errno));
                                unlink(tmpfname);
                                exit(1);
                        }
@@ -320,7 +320,11 @@ finish_file(void)
                        if (outfile != NULL && outfile != stdout)
                                fclose(outfile);
                        outfile = NULL;
-                       rename(tmpfname, fname);
+                       if (rename(tmpfname, fname) != 0) {
+                               warning("rename(): %s", strerror(errno));
+                               unlink(tmpfname);
+                               exit(1);
+                       }
                        *tmpfname = '\0';
                }
                outfname = NULL;
@@ -377,7 +381,7 @@ mf_getline(SPACE *sp, enum e_spflag spflag)
                }
                fname = files->fname;
                if (inplace != NULL) {
-                       if (lstat(fname, &sb) != 0)
+                       if (stat(fname, &sb) != 0)
                                error(FATAL, "%s: %s", fname,
                                    strerror(errno ? errno : EIO));
                        if (!S_ISREG(sb.st_mode))
@@ -399,12 +403,12 @@ mf_getline(SPACE *sp, enum e_spflag spflag)
                                error(FATAL, "%s: name too long", fname);
                        if ((fd = mkstemp(tmpfname)) == -1)
                                error(FATAL, "%s: %s", fname, strerror(errno));
+                       (void)fchown(fd, sb.st_uid, sb.st_gid);
+                       (void)fchmod(fd, sb.st_mode & ALLPERMS);
                        if ((outfile = fdopen(fd, "w")) == NULL) {
                                unlink(tmpfname);
                                error(FATAL, "%s", fname);
                        }
-                       fchown(fileno(outfile), sb.st_uid, sb.st_gid);
-                       fchmod(fileno(outfile), sb.st_mode & ALLPERMS);
                        outfname = tmpfname;
                        linenum = 0;
                        resetstate();