lsns: initialize stuff when really necessary

It's more robust to depend on list of the wanted columns than on
another variables.

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/lsns.8 b/sys-utils/lsns.8
index 4d108a48c0cc66e6d8293e430d7c75c054a14f45..94b82a0cb19b4719effdbfb6d62404b53011cedc 100644 (file)
--- a/sys-utils/lsns.8
+++ b/sys-utils/lsns.8
@@ -22,7 +22,7 @@ environments where a stable output is required.
 
 \fBNSFS\fP column, printed when \fBnet\fP is specified for
 \fB\-\-type\fR option, is specifal; it uses multi-line cells.
-\fB\-\-nowrap\fR is for switching to "," separated single-line
+Use the option \fB\-\-nowrap\fR is for switching to "," separated single-line
 representation.
 
 Note that \fBlsns\fR reads information directly from the /proc filesystem and

diff --git a/sys-utils/lsns.c b/sys-utils/lsns.c
index 19044fbfecce5ac5ddb95555dd1c22f8941207b6..eea04c73ccfbd4821146d5090fe317b8a0aa1daa 100644 (file)
--- a/sys-utils/lsns.c
+++ b/sys-utils/lsns.c
@@ -102,8 +102,8 @@ static const struct colinfo infos[] = {
        [COL_COMMAND] = { "COMMAND", 0, SCOLS_FL_TRUNC, N_("command line of the PID")},
        [COL_UID]     = { "UID",     0, SCOLS_FL_RIGHT, N_("UID of the PID")},
        [COL_USER]    = { "USER",    0, 0, N_("username of the PID")},
-       [COL_NETNSID] = { "NETNSID", 0, SCOLS_FL_RIGHT, N_("Net namespace ID")},
-       [COL_NSFS]    = { "NSFS",    0, SCOLS_FL_WRAP, N_("Logical name established by nsfs")}
+       [COL_NETNSID] = { "NETNSID", 0, SCOLS_FL_RIGHT, N_("namespace ID as used by network subsystem")},
+       [COL_NSFS]    = { "NSFS",    0, SCOLS_FL_WRAP, N_("nsfs mountpoint (usually used network subsystem)")}
 };
 
 static int columns[ARRAY_SIZE(infos) * 2];
@@ -221,6 +221,17 @@ static int column_name_to_id(const char *name, size_t namesz)
        return -1;
 }
 
+static int has_column(int id)
+{
+       size_t i;
+
+       for (i = 0; i < ncolumns; i++) {
+               if (columns[i] == id)
+                       return 1;
+       }
+       return 0;
+}
+
 static inline int get_column_id(int num)
 {
        assert(num >= 0);
@@ -936,7 +947,7 @@ int main(int argc, char *argv[])
                { 0 }
        };
        int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
-       int enabling_netnsid = 0;
+       int is_net = 0;
 
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
@@ -990,7 +1001,7 @@ int main(int argc, char *argv[])
                        ls.fltr_types[type] = 1;
                        ls.fltr_ntypes++;
                        if (type == LSNS_ID_NET)
-                               enabling_netnsid = 1;
+                               is_net = 1;
                        break;
                }
                case 'W':
@@ -1028,27 +1039,17 @@ int main(int argc, char *argv[])
                columns[ncolumns++] = COL_NPROCS;
                columns[ncolumns++] = COL_PID;
                columns[ncolumns++] = COL_USER;
-               if (enabling_netnsid) {
+               if (is_net) {
                        columns[ncolumns++] = COL_NETNSID;
                        columns[ncolumns++] = COL_NSFS;
                }
                columns[ncolumns++] = COL_COMMAND;
        }
 
-       if (outarg) {
-               size_t i;
-
-               if (string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns),
-                                         &ncolumns, column_name_to_id) < 0)
-                       return EXIT_FAILURE;
+       if (outarg && string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns),
+                                 &ncolumns, column_name_to_id) < 0)
+               return EXIT_FAILURE;
 
-               for (i = 0; i < ncolumns; i++) {
-                       if (columns[i] == COL_NETNSID) {
-                               enabling_netnsid = 1;
-                               break;
-                       }
-               }
-       }
        scols_init_debug(0);
 
        uid_cache = new_idcache();
@@ -1056,12 +1057,14 @@ int main(int argc, char *argv[])
                err(EXIT_FAILURE, _("failed to allocate UID cache"));
 
 #ifdef HAVE_LINUX_NET_NAMESPACE_H
-       if (enabling_netnsid)
+       if (has_column(COL_NETNSID))
                netlink_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 #endif
-       ls.tab = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
-       if (!ls.tab)
-               err(MNT_EX_FAIL, _("failed to parse %s"), _PATH_PROC_MOUNTINFO);
+       if (has_column(COL_NSFS)) {
+               ls.tab = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
+               if (!ls.tab)
+                       err(MNT_EX_FAIL, _("failed to parse %s"), _PATH_PROC_MOUNTINFO);
+       }
 
        r = read_processes(&ls);
        if (!r)