Hi, I noticed that when doing `sed -i` on a file you don't have permission to read, the error message printed isn't very helpful:
$ sed -i '/test/d' /var/log/Xorg.1.log.old sed: /var/log/Xorg.1.log.old The patch below seems to fix the issue for me: $ ./sed -i '/test/d' /var/log/Xorg.1.log.old sed: /var/log/Xorg.1.log.old: Permission denied Regards, Michael Index: main.c =================================================================== RCS file: /cvs/src/usr.bin/sed/main.c,v retrieving revision 1.30 diff -u -p -r1.30 main.c --- main.c 26 Oct 2015 22:22:56 -0000 1.30 +++ main.c 1 Jan 2016 19:17:16 -0000 @@ -374,7 +374,7 @@ mf_fgets(SPACE *sp, enum e_spflag spflag if (len >= sizeof(tmpfname)) error(FATAL, "%s: name too long", fname); if ((fd = mkstemp(tmpfname)) == -1) - error(FATAL, "%s", fname); + error(FATAL, "%s: %s", fname, strerror(errno)); if ((outfile = fdopen(fd, "w")) == NULL) { unlink(tmpfname); error(FATAL, "%s", fname);