From 840d92358e311b405475ba7488ec55cc3f4f5fae Mon Sep 17 00:00:00 2001
From: Jari Vetoniemi <mailroxas@gmail.com>
Date: Sun, 21 Oct 2018 19:48:24 +0300
Subject: Give binsearch ability to find all matches

---
 src/binsearch.c | 51 ++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 38 insertions(+), 13 deletions(-)

(limited to 'src/binsearch.c')

diff --git a/src/binsearch.c b/src/binsearch.c
index a4195ba..d382c5a 100644
--- a/src/binsearch.c
+++ b/src/binsearch.c
@@ -2,12 +2,16 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
+#include <util.h>
 #include <err.h>
 
+static bool FOUND = false;
+
 static void
 usage(const char *argv0)
 {
-   fprintf(stderr, "usage: %s needle [window-size] < haystack\n", argv0);
+   fprintf(stderr, "usage: %s needle first [window-size] < haystack\n"
+                   "       %s needle all [window-size] < haystack\n", argv0, argv0);
    exit(EXIT_FAILURE);
 }
 
@@ -23,14 +27,17 @@ search(const char *haystack, const char *needle, const size_t window_size)
 }
 
 static void
-search_and_exit_if_match(const char *haystack, const char *needle, const size_t window_size, const size_t offset)
+search_and_print_if_match(const char *haystack, const char *needle, const size_t window_size, const size_t offset, const bool exit_on_match)
 {
    const char *match;
    if ((match = search(haystack, needle, window_size))) {
+      FOUND = true;
       printf("%zu\n", offset + match - haystack);
-      free((void*)needle);
-      free((void*)haystack);
-      exit(EXIT_SUCCESS);
+      if (exit_on_match) {
+         free((void*)needle);
+         free((void*)haystack);
+         exit(EXIT_SUCCESS);
+      }
    }
 }
 
@@ -41,10 +48,23 @@ main(int argc, const char *argv[])
    size_t window_size = 4096 * 1024;
    bool has_window_size = false;
 
-   if (argc < 2)
+   if (argc < 3)
       usage(argv[0]);
-   else if (argc > 2) {
-      window_size = strtoull(argv[2], NULL, 10);
+
+   enum {
+      FIRST,
+      ALL
+   } mode;
+
+   if (!strcmp(argv[2], "first"))
+      mode = FIRST;
+   else if (!strcmp(argv[2], "all"))
+      mode = ALL;
+   else
+      errx(EXIT_FAILURE, "mode must be first or all");
+
+   if (argc > 3) {
+      window_size = hexdecstrtoull(argv[3], NULL);
       has_window_size = true;
    }
 
@@ -55,7 +75,12 @@ main(int argc, const char *argv[])
    if (!has_window_size) {
       fseek(f, 0, SEEK_END);
       const long tell = ftell(f);
-      window_size = (tell > 0 ? (size_t)tell : window_size);
+
+      if (tell < 0)
+         warnx("can't figure out the size of a needle, not a normal file? fallbacking to a window size of %zu bytes", window_size);
+      else
+         window_size = tell;
+
       fseek(f, 0, SEEK_SET);
    }
 
@@ -71,14 +96,14 @@ main(int argc, const char *argv[])
          err(EXIT_FAILURE, "calloc");
 
    size_t rd = 0, offset = 0;
-   while ((rd = fread(haystack + window_size * !!offset, 1 + !offset, window_size, stdin))) {
-      search_and_exit_if_match(haystack, needle, (rd >= window_size ? window_size : 0), offset);
+   while ((rd = fread(haystack + window_size * !!offset, 1, window_size * (1 + !offset), stdin))) {
+      search_and_print_if_match(haystack, needle, (rd >= window_size ? window_size : 0), offset, (mode == FIRST));
       offset += window_size;
       memmove(haystack, haystack + window_size, window_size);
    }
 
-   search_and_exit_if_match(haystack, needle, (rd >= window_size ? window_size : 0), offset);
+   search_and_print_if_match(haystack, needle, (rd >= window_size ? window_size : 0), offset, (mode == FIRST));
    free(needle);
    free(haystack);
-   return EXIT_FAILURE;
+   return (FOUND ? EXIT_SUCCESS : EXIT_FAILURE);
 }
-- 
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