brctl: optional support for "show" cmd (by L. Gabriel Somlo <somlo AT cmu.edu>)

function                                             old     new   delta
brctl_main                                           739    1186    +447
if_indextoname                                         -     104    +104
static.keywords                                      827     841     +14
static.ops                                             -       7      +7
packed_usage                                       23978   23976      -2

2 files changed, 8 insertions, 4 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 202574adb..1c54a32d5 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1017,15 +1017,15 @@ extern int update_passwd(const char *filename, const char *username,
 int get_terminal_width_height(int fd, int *width, int *height);
 
 int ioctl_or_perror(int fd, int request, void *argp, const char *fmt,...) __attribute__ ((format (printf, 4, 5)));
-void ioctl_or_perror_and_die(int fd, int request, void *argp, const char *fmt,...) __attribute__ ((format (printf, 4, 5)));
+int ioctl_or_perror_and_die(int fd, int request, void *argp, const char *fmt,...) __attribute__ ((format (printf, 4, 5)));
 #if ENABLE_IOCTL_HEX2STR_ERROR
 int bb_ioctl_or_warn(int fd, int request, void *argp, const char *ioctl_name);
-void bb_xioctl(int fd, int request, void *argp, const char *ioctl_name);
+int bb_xioctl(int fd, int request, void *argp, const char *ioctl_name);
 #define ioctl_or_warn(fd,request,argp) bb_ioctl_or_warn(fd,request,argp,#request)
 #define xioctl(fd,request,argp)        bb_xioctl(fd,request,argp,#request)
 #else
 int bb_ioctl_or_warn(int fd, int request, void *argp);
-void bb_xioctl(int fd, int request, void *argp);
+int bb_xioctl(int fd, int request, void *argp);
 #define ioctl_or_warn(fd,request,argp) bb_ioctl_or_warn(fd,request,argp)
 #define xioctl(fd,request,argp)        bb_xioctl(fd,request,argp)
 #endif
diff --git a/include/usage.h b/include/usage.h
index 0849c6831..e007acdfa 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -138,6 +138,9 @@
 #define brctl_full_usage \
        "Manage ethernet bridges.\n" \
      "\nCommands:" \
+        USE_FEATURE_BRCTL_SHOW( \
+     "\n        show                    Show a list of bridges" \
+        ) \
      "\n        addbr BRIDGE            Create BRIDGE" \
      "\n        delbr BRIDGE            Delete BRIDGE" \
      "\n        addif BRIDGE IFACE      Add IFACE to BRIDGE" \
@@ -151,7 +154,8 @@
      "\n        setportprio BRIDGE PRIO         Set port priority" \
      "\n        setbridgeprio BRIDGE PRIO       Set bridge priority" \
      "\n        stp BRIDGE [1|0]                STP on/off" \
-        )
+        ) \
+
 #define bunzip2_trivial_usage \
        "[OPTION]... [FILE]"
 #define bunzip2_full_usage \