diff --git a/recover-pdfs.c b/recover-pdfs.c
index ba530fa..d77156c 100644
--- a/recover-pdfs.c
+++ b/recover-pdfs.c
@@ -4,17 +4,31 @@
 #include <sys/stat.h>
 
 #define CHUNK 4096
+#define MAX_PDF_SIZE (100LL * 1024 * 1024)  // 100 MB
 
-int match_at(const unsigned char *buf, size_t len, const char *pat) {
-    size_t p = strlen(pat);
-    if (len < p) return 0;
-    return memcmp(buf, pat, p) == 0;
+int valid_pdf_header(const unsigned char *buf, size_t len) {
+    if (len < 9) return 0;
+
+    if (memcmp(buf, "%PDF-", 5) != 0)
+        return 0;
+
+    if (buf[5] < '0' || buf[5] > '9') return 0;
+    if (buf[6] != '.') return 0;
+    if (buf[7] < '0' || buf[7] > '9') return 0;
+
+    size_t i = 8;
+
+    if (buf[i] >= '0' && buf[i] <= '9') i++;
+
+    if (buf[i] == '\r' && buf[i + 1] == '\n') return 1;
+    if (buf[i] == '\n') return 1;
+
+    return 0;
 }
 
-size_t find_in_buffer(const unsigned char *buf, size_t len, const char *pat) {
-    size_t p = strlen(pat);
-    for (size_t i = 0; i + p <= len; i++) {
-        if (memcmp(buf + i, pat, p) == 0)
+size_t find_eof(const unsigned char *buf, size_t len) {
+    for (size_t i = 0; i + 5 <= len; i++) {
+        if (memcmp(buf + i, "%%EOF", 5) == 0)
             return i;
     }
     return (size_t)-1;
@@ -42,6 +56,9 @@ int main(int argc, char **argv) {
 
     mkdir(outdir, 0755);
 
+		if (strcmp(infile, "-") == 0) {
+				infile = "/dev/stdin";
+		}
     FILE *f = fopen(infile, "rb");
     if (!f) {
         perror("open input");
@@ -50,11 +67,12 @@ int main(int argc, char **argv) {
 
     unsigned char *buf = malloc(CHUNK * 2);
     size_t buf_len = 0;
-    int pdf_count = 0;
 
-    unsigned char *file_data = NULL;
-    size_t file_size = 0;
+    unsigned char *pdf_buf = NULL;
+    size_t pdf_size = 0;
+
     int collecting = 0;
+    int pdf_count = 0;
 
     while (!feof(f)) {
         size_t r = fread(buf + buf_len, 1, CHUNK, f);
@@ -65,28 +83,40 @@ int main(int argc, char **argv) {
         while (i < buf_len) {
 
             if (!collecting) {
-                if (i + 5 < buf_len && memcmp(buf + i, "%PDF-", 5) == 0) {
+                if (i + 10 < buf_len && valid_pdf_header(buf + i, buf_len - i)) {
                     collecting = 1;
-                    file_data = malloc(1024);
-                    file_size = 0;
+                    pdf_buf = malloc(1024);
+                    pdf_size = 0;
                 }
             }
 
             if (collecting) {
-                if (file_size % 1024 == 0) {
-                    file_data = realloc(file_data, file_size + 1024);
+
+                // HARD SIZE LIMIT CHECK
+                if (pdf_size >= MAX_PDF_SIZE) {
+                    free(pdf_buf);
+                    pdf_buf = NULL;
+                    pdf_size = 0;
+                    collecting = 0;
+                    continue;
                 }
 
-                file_data[file_size++] = buf[i];
+                if (pdf_size % 1024 == 0) {
+                    pdf_buf = realloc(pdf_buf, pdf_size + 1024);
+                }
 
-                if (file_size > 6) {
-                    if (memmem(file_data, file_size, "%%EOF", 5)) {
-                        write_pdf(file_data, file_size, pdf_count++, outdir);
-                        free(file_data);
-                        file_data = NULL;
-                        file_size = 0;
-                        collecting = 0;
-                    }
+                pdf_buf[pdf_size++] = buf[i];
+
+                size_t eof_pos = find_eof(pdf_buf, pdf_size);
+                if (eof_pos != (size_t)-1) {
+                    size_t end = eof_pos + 5;
+
+                    write_pdf(pdf_buf, end, pdf_count++, outdir);
+
+                    free(pdf_buf);
+                    pdf_buf = NULL;
+                    pdf_size = 0;
+                    collecting = 0;
                 }
             }