added progressbar for monitoring file stream position via procfs

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

2 files changed, 113 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index cbc4a0e..2a00739 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ CFLAGS := -O2 -g -Wall -ffunction-sections -fdata-sections -ffast-math -fomit-fr
 LDFLAGS :=
 RM := rm -rf
 
-TARGETS := aes asciihexer dummyshell suidcmd scrambler
+TARGETS := aes asciihexer dummyshell suidcmd scrambler progressbar
 
 ifneq ($(strip $(MAKE_NCURSES)),)
 TARGETS += gol
@@ -62,6 +62,13 @@ xdiff: xdiff.o
 	@echo 'Finished building target: $@'
 	@echo ' '
 
+progressbar: progressbar.o
+	@echo 'Building target: $@'
+	@echo 'Invoking: GCC C Linker'
+	$(CC) $(LDFLAGS)  -o "$@" "$<"
+	@echo 'Finished building target: $@'
+	@echo ' '
+
 strip:
 	strip -s $(TARGETS)
 
diff --git a/progressbar.c b/progressbar.c
new file mode 100644
index 0000000..a8c183e
--- /dev/null
+++ b/progressbar.c
@@ -0,0 +1,105 @@
+#define _DEFAULT_SOURCE
+#include <dirent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+struct filtered_dir_entries {
+    struct dirent ** entries;
+    size_t entries_num;
+};
+
+
+static int search_dir(const char * const dir,
+                      int (*filter_fn)(const struct dirent *),
+                      struct filtered_dir_entries * const entries)
+{
+    struct dirent **names;
+    int n;
+
+    n = scandir(dir, &names, filter_fn, alphasort);
+    if (n < 0) {
+        perror("scandir");
+        return 1;
+    }
+
+    entries->entries = names;
+    entries->entries_num = n;
+
+    return 0;
+}
+
+static int dirent_filter_only_numeric(const struct dirent * ent)
+{
+    char * end_ptr;
+
+    errno = 0;
+    strtoul(ent->d_name, &end_ptr, 10);
+    return (errno != 0 || *end_ptr == '\0');
+}
+
+static int search_procfs_fd(const char * const dir, const char * const subdir,
+                              struct filtered_dir_entries * const entries)
+{
+    char buf[BUFSIZ];
+
+    snprintf(buf, sizeof buf, "%s/%s/fd", dir ,subdir);
+    return search_dir(buf, dirent_filter_only_numeric, entries);
+}
+
+static ssize_t realpath_procfs_fd(const char * const dir, const char * const pid,
+                                  const char * const fd, char * dest, size_t siz)
+{
+    char buf[BUFSIZ];
+
+    snprintf(buf, sizeof buf, "%s/%s/fd/%s", dir, pid, fd);
+    return readlink(buf, dest, siz);
+}
+
+static void free_filtered_dir_entries(struct filtered_dir_entries * const entries)
+{
+    if (!entries->entries) {
+        return;
+    }
+    for (size_t i = 0; i < entries->entries_num; ++i) {
+        free(entries->entries[i]);
+    }
+    free(entries->entries);
+    entries->entries = NULL;
+    entries->entries_num = 0;
+}
+
+int main(int argc, char **argv)
+{
+    struct filtered_dir_entries proc_pid_entries = {};
+    struct filtered_dir_entries proc_fd_entries = {};
+    ssize_t realpath_used;
+    char realpath[BUFSIZ];
+
+    (void) argc;
+    (void) argv;
+
+    if (search_dir("/proc", dirent_filter_only_numeric, &proc_pid_entries)) {
+        exit(EXIT_FAILURE);
+    }
+    for (size_t i = 0; i < proc_pid_entries.entries_num; ++i) {
+        if (search_procfs_fd("/proc", proc_pid_entries.entries[i]->d_name,
+                             &proc_fd_entries)) {
+            continue;
+        }
+
+        for (size_t j = 0; j < proc_fd_entries.entries_num; ++j) {
+            realpath_used = realpath_procfs_fd("/proc",
+                                proc_pid_entries.entries[i]->d_name,
+                                proc_fd_entries.entries[j]->d_name,
+                                &realpath[0], sizeof realpath);
+            if (realpath_used < 0) {
+                continue;
+            }
+            printf("%s: __%.*s__\n", proc_pid_entries.entries[i]->d_name, (int)realpath_used, realpath);
+        }
+        free_filtered_dir_entries(&proc_fd_entries);
+    }
+    free_filtered_dir_entries(&proc_pid_entries);
+}