lsfd: introduce --source filter option

Reflecting the review comment:

    add filter by SOURCE (lsfd --source sda1)

Example output:

    # ./lsfd --source proc | head
    COMMAND             PID   USER ASSOC MODE TYPE SOURCE MNTID      INODE NAME
    systemd               1   root    10  r--  REG   proc    23      18542 /proc/1/mountinfo
    systemd               1   root    14  r--  REG   proc    23 4026532082 /proc/swaps
    systemd-resolve     856   root     7  r--  REG   proc   254      24841 /proc/sys/kernel/hostname
    low-memory-moni     898   root     7  rw-  REG   proc   425 4026532073 /proc/pressure/memory
    low-memory-moni     898   root     8  rw-  REG   proc   425 4026532073 /proc/pressure/memory
    low-memory-moni     898   root     9  rw-  REG   proc   425 4026532073 /proc/pressure/memory
    packagekitd       25205   root    12  r--  REG   proc    23      69645 /proc/25205/mountinfo
    systemd           26466   root    10  r--  REG   proc    23      71813 /proc/26466/mountinfo
    systemd           26466   root    14  r--  REG   proc    23 4026532082 /proc/swaps

    # ./lsfd --source proc -Q '(PID == 898)'
    COMMAND           PID USER ASSOC MODE TYPE SOURCE MNTID      INODE NAME
    low-memory-moni   898 root     7  rw-  REG   proc   425 4026532073 /proc/pressure/memory
    low-memory-moni   898 root     8  rw-  REG   proc   425 4026532073 /proc/pressure/memory
    low-memory-moni   898 root     9  rw-  REG   proc   425 4026532073 /proc/pressure/memory

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index 1662cf9698d67764d26fcec395ca2ab13524aae5..8da659fbc3c1b83e9033c3e141383ebb3e93aec1 100644 (file)
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -941,6 +941,7 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_("     --sysroot <dir>   use specified directory as system root\n"), out);
        fputs(_(" -u, --notruncate      don't truncate text in columns\n"), out);
        fputs(_(" -Q, --filter <expr>   apply display filter\n"), out);
+       fputs(_("     --source <source> add filter by SOURCE\n"), out);
 
        fputs(USAGE_SEPARATOR, out);
        printf(USAGE_HELP_OPTIONS(23));
@@ -965,6 +966,28 @@ static void xstrappend(char **a, const char *b)
                err(EXIT_FAILURE, _("failed to allocate memory for string"));
 }
 
+static char * quote_filter_expr(char *expr)
+{
+       char c[] = {'\0', '\0'};
+       char *r = strdup("");
+       while (*expr) {
+               switch (*expr) {
+               case '\'':
+                       xstrappend(&r, "\\'");
+                       break;
+               case '"':
+                       xstrappend(&r, "\\\"");
+                       break;
+               default:
+                       c[0] = *expr;
+                       xstrappend(&r, c);
+                       break;
+               }
+               expr++;
+       }
+       return r;
+}
+
 static void append_filter_expr(char **a, const char *b, bool and)
 {
        if (*a == NULL) {
@@ -995,7 +1018,8 @@ int main(int argc, char *argv[])
        char  *filter_expr = NULL;
 
        enum {
-               OPT_SYSROOT = CHAR_MAX + 1
+               OPT_SYSROOT = CHAR_MAX + 1,
+               OPT_SOURCE,
        };
        static const struct option longopts[] = {
                { "noheadings", no_argument, NULL, 'n' },
@@ -1008,6 +1032,7 @@ int main(int argc, char *argv[])
                { "notruncate", no_argument, NULL, 'u' },
                { "sysroot",    required_argument, NULL, OPT_SYSROOT },
                { "filter",     required_argument, NULL, 'Q' },
+               { "source",     required_argument, NULL, OPT_SOURCE },
                { NULL, 0, NULL, 0 },
        };
 
@@ -1042,6 +1067,17 @@ int main(int argc, char *argv[])
                case 'Q':
                        append_filter_expr(&filter_expr, optarg, true);
                        break;
+               case OPT_SOURCE: {
+                       char * quoted_source = quote_filter_expr(optarg);
+                       char * source_expr = NULL;
+                       xstrappend(&source_expr, "(SOURCE == '");
+                       xstrappend(&source_expr, quoted_source);
+                       xstrappend(&source_expr, "')");
+                       append_filter_expr(&filter_expr, source_expr, true);
+                       free(source_expr);
+                       free(quoted_source);
+                       break;
+               }
 
                case 'V':
                        print_version(EXIT_SUCCESS);