Add -f option to make using this in scripts easier

src/main.c

@@ -15,7 +15,7 @@
 static_assert((sizeof(long long) >= 8), "Size of long long is less than 8, cannot compile");
 
 void usage() {
-    fprintf(stderr, "Usage: " PROGRAM_NAME " [-h | -i | -s] [-n] [-v data_path] [--] .torrent_file...\n");
+    fprintf(stderr, "Usage: " PROGRAM_NAME " [-h | -i | -s | -f CHAR] [-n] [-v data_path] [--] .torrent_file...\n");
     exit(EXIT_FAILURE);
 }
 
@@ -30,6 +30,8 @@ void help() {
 "   -v PATH   verify the torrent file, pass in the path of the files\n"
 "   -s        don't write any output\n"
 "   -n        Don't use torrent name as a folder when verifying\n"
+"   -f CHAR   Show info from the .torrent file, as an input for a script\n"
+"             Valid CHARs are: i - Info hash\n"
 "\n"
 "EXIT CODE\n"
 "   If no error, exit code is 0. In verify mode exit code is 0 if it's\n"
@@ -56,12 +58,6 @@ int main(int argc, char** argv) {
         fprintf(stderr, "Provide at least one torrent file\n");
         usage();
     }
-    /*
-    if (data_path && optind != argc - 1) {
-        fprintf(stderr, "If used with -v, only input 1 bittorrent file\n");
-        usage();
-    }
-    */
     
     int exit_code = EXIT_SUCCESS;
     for (int i = optind; i < argc; i++) {
@@ -74,6 +70,10 @@ int main(int argc, char** argv) {
             showinfo(&m);
         }
 
+        if (opt_scriptformat_info != OPT_SCRIPTFORMAT_NONE) {
+            showinfo_script(&m);
+        }
+
         if (opt_data_path) { /* Verify */
             int verify_result = verify(&m, opt_data_path, !opt_no_use_dir);
             if (verify_result != 0) {

src/opts.c

@@ -1,17 +1,19 @@
 #include "opts.h"
 #include <unistd.h>
+#include <string.h>
 
 int opt_silent = 0;
 int opt_showinfo = 0;
 int opt_help = 0;
 int opt_no_use_dir = 0;
 int opt_pretty_progress = 0;
+int opt_scriptformat_info = OPT_SCRIPTFORMAT_NONE;
 char* opt_data_path = NULL;
 
 int opts_parse(int argc, char** argv) {
     int opt;
 
-    while ((opt = getopt(argc, argv, "pnihsv:")) != -1) {
+    while ((opt = getopt(argc, argv, "pnihsv:f:")) != -1) {
         switch (opt) {
             case 'i':
                 opt_showinfo = 1;
@@ -31,6 +33,21 @@ int opts_parse(int argc, char** argv) {
             case 'v':
                 opt_data_path = optarg;
                 break;
+            case 'f':
+                if (strlen(optarg) != 1)
+                    return -1;
+                char info_char = optarg[0];
+                opt_scriptformat_info = OPT_SCRIPTFORMAT_INVALID;
+                for (int i = 0; i < OPT_SCRIPTFORMAT_MAPPING_LEN; i++) {
+                    const opt_scriptformat_mapping_t* curr = &OPT_SCRIPTFORMAT_MAPPING[i];
+                    if (info_char == curr->info_char) {
+                        opt_scriptformat_info = curr->info;
+                        break;
+                    }
+                }
+                if (opt_scriptformat_info == OPT_SCRIPTFORMAT_INVALID)
+                    return -1;
+                break;
             default:
                 return -1;
         }

src/opts.h

@@ -1,11 +1,29 @@
 #ifndef OPTS_H
 #define OPTS_H
 
+enum OPT_SCRIPTFORMAT {
+    OPT_SCRIPTFORMAT_INVALID = -1,
+    OPT_SCRIPTFORMAT_NONE,
+    OPT_SCRIPTFORMAT_INFOHASH,
+};
+
+typedef struct {
+    char info_char;
+    enum OPT_SCRIPTFORMAT info;
+} opt_scriptformat_mapping_t;
+
+const static opt_scriptformat_mapping_t OPT_SCRIPTFORMAT_MAPPING[] = {
+    { .info_char = 'i', .info = OPT_SCRIPTFORMAT_INFOHASH },
+};
+#define OPT_SCRIPTFORMAT_MAPPING_LEN sizeof(OPT_SCRIPTFORMAT_MAPPING)/sizeof(OPT_SCRIPTFORMAT_MAPPING[0])
+
+
 extern int opt_silent;
 extern int opt_showinfo;
 extern int opt_help;
 extern int opt_no_use_dir;
 extern int opt_pretty_progress;
+extern int opt_scriptformat_info;
 extern char* opt_data_path;
 
 /* Parse the given arguments. Return -1 if error */

src/showinfo.c

@@ -3,6 +3,7 @@
 #include <time.h>
 #include "showinfo.h"
 #include "util.h"
+#include "opts.h"
 
 void showinfo(metainfo_t* m) {
     const char* s;
@@ -95,3 +96,20 @@ void showinfo(metainfo_t* m) {
         strncpy(str_buff, "err", sizeof(str_buff));
     printf("Total size: %s\n", str_buff);
 }
+
+void showinfo_script(metainfo_t* m) {
+    switch (opt_scriptformat_info) {
+    case OPT_SCRIPTFORMAT_INFOHASH:
+    {
+        char hex_str[sizeof(sha1sum_t)*2+1];
+        const sha1sum_t* infohash = metainfo_infohash(m);
+        util_byte2hex((const unsigned char*)infohash, sizeof(sha1sum_t), 0, hex_str);
+        printf("%s\n", hex_str);
+        break;
+    }
+    default:
+        printf("Unknown?? [>.<]\n");
+        break;
+    }
+}
+

src/showinfo.h

@@ -7,4 +7,10 @@
  */
 void showinfo(metainfo_t* m);
 
+/*
+ * Print the selected info from the metainfo file 
+ * to be readable by a script
+ */
+void showinfo_script(metainfo_t* m);
+
 #endif