[hackers] [sbase] chmod: Remove -HLP flags, and ignore symlinks during traversal || Michael Forney

[git]

commit 3e160b616a183798e3dba34b93651a27851b1886
Author:     Michael Forney <mfor...@mforney.org>
AuthorDate: Sat Dec 21 21:47:55 2019 -0800
Commit:     Michael Forney <mfor...@mforney.org>
CommitDate: Thu Mar 5 00:45:44 2020 -0800

    chmod: Remove -HLP flags, and ignore symlinks during traversal
    
    These flags are non-POSIX and not useful since the mode of symlinks
    is not used for anything.
    
    This prevents a failure when a dangling symlink is encountered
    during a recursive chmod.

diff --git a/chmod.1 b/chmod.1
index 5ca1ce1..9139351 100644
--- a/chmod.1
+++ b/chmod.1
@@ -1,4 +1,4 @@
-.Dd 2015-10-08
+.Dd 2019-12-21
 .Dt CHMOD 1
 .Os sbase
 .Sh NAME
@@ -6,10 +6,7 @@
 .Nd change file modes
 .Sh SYNOPSIS
 .Nm
-.Oo
-.Fl R
-.Op Fl H | L | P
-.Oc
+.Op Fl R
 .Ar mode
 .Ar file ...
 .Sh DESCRIPTION
@@ -58,19 +55,13 @@ read | write | execute | setuid and setgid | sticky
 .It X
 execute, if directory or at least one execute bit is already set
 .El
+.Pp
+Symbolic links are followed if they are passed as operands, and ignored
+if they are encountered during directory traversal.
 .Sh OPTIONS
 .Bl -tag -width Ds
 .It Fl R
 Change modes recursively.
-.It Fl H
-Dereference
-.Ar file
-if it is a symbolic link.
-.It Fl L
-Dereference all symbolic links.
-.It Fl P
-Preserve symbolic links.
-This is the default.
 .El
 .Sh SEE ALSO
 .Xr chgrp 1 ,
diff --git a/chmod.c b/chmod.c
index 512a7ea..7b9afe8 100644
--- a/chmod.c
+++ b/chmod.c
@@ -14,7 +14,7 @@ chmodr(const char *path, struct stat *st, void *data, struct 
recursor *r)
        mode_t m;
 
        m = parsemode(modestr, st->st_mode, mask);
-       if (chmod(path, m) < 0) {
+       if (!S_ISLNK(st->st_mode) && chmod(path, m) < 0) {
                weprintf("chmod %s:", path);
                ret = 1;
        } else if (S_ISDIR(st->st_mode)) {
@@ -25,14 +25,14 @@ chmodr(const char *path, struct stat *st, void *data, 
struct recursor *r)
 static void
 usage(void)
 {
-       eprintf("usage: %s [-R [-H | -L | -P]] mode file ...\n", argv0);
+       eprintf("usage: %s [-R] mode file ...\n", argv0);
 }
 
 int
 main(int argc, char *argv[])
 {
        struct recursor r = { .fn = chmodr, .hist = NULL, .depth = 0, .maxdepth 
= 1,
-                             .follow = 'P', .flags = DIRFIRST };
+                             .follow = 'H', .flags = DIRFIRST };
        size_t i;
 
        argv0 = *argv, argv0 ? (argc--, argv++) : (void *)0;
@@ -45,11 +45,6 @@ main(int argc, char *argv[])
                        case 'R':
                                r.maxdepth = 0;
                                break;
-                       case 'H':
-                       case 'L':
-                       case 'P':
-                               r.follow = (*argv)[i];
-                               break;
                        case 'r': case 'w': case 'x': case 'X': case 's': case 
't':
                                /* -[rwxXst] are valid modes, so we're done */
                                if (i == 1)