Add option --list-file-types

This patch documents the file types which were made searchable in ggreer#283

doc/ag.1

@@ -1,13 +1,13 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "AG" "1" "September 2013" "" ""
+.TH "AG" "1" "January 2014" "" ""
 .
 .SH "NAME"
 \fBag\fR \- The Silver Searcher\. Like ack, but faster\.
 .
 .SH "SYNOPSIS"
-\fBag\fR [\fIoptions\fR] PATTERN [PATH]
+\fBag\fR [\fIfile\-type\fR] [\fIoptions\fR] PATTERN [PATH]
 .
 .SH "DESCRIPTION"
 Recursively search for PATTERN in PATH\. Like grep or ack, but faster\.
@@ -151,6 +151,12 @@ Recursively search for PATTERN in PATH\. Like grep or ack, but faster\.
 \~\~\~\~ Only print filenames that don\'t contain matches\.
 .
 .P
+\fB\-\-list\-file\-types\fR:
+.
+.br
+\~\~\~\~ See \fBFILE TYPES\fR below\.
+.
+.P
 \fB\-m \-\-max\-count NUM\fR:
 .
 .br
@@ -237,7 +243,10 @@ Recursively search for PATTERN in PATH\. Like grep or ack, but faster\.
 .br
 \~\~\~\~ Only match whole words\.
 .
-.P
+.SH "FILE TYPES"
+It is possible to restrict the types of files searched\. For example, passing \fB\-\-html\fR as the \fBfile\-types\fR parameter will search only files with the extensions \fBhtm\fR, \fBhtml\fR, \fBshtml\fR or \fBxhtml\fR\. For a list of supported \fBfile\-types\fR run \fBag \-\-list\-file\-types\fR\.
+.
+.SH "IGNORING FILES"
 By default, ag will ignore files matched by patterns in \.gitignore, \.hgignore, or \.agignore\. These files can be anywhere in the directories being searched\. Ag also ignores files matched by the svn:ignore property in subversion repositories\. Finally, ag looks in $HOME/\.agignore for ignore patterns\. Binary files are ignored by default as well\.
 .
 .P

doc/ag.1.md

@@ -3,7 +3,7 @@ ag(1) -- The Silver Searcher. Like ack, but faster.
 
 ## SYNOPSIS
 
-`ag` [<options>] PATTERN [PATH]
+`ag` [<file-type>] [<options>] PATTERN [PATH]
 
 ## DESCRIPTION
 
@@ -57,6 +57,8 @@ Recursively search for PATTERN in PATH. Like grep or ack, but faster.
     Only print filenames containing matches, not matching lines. An empty query will print all files that would be searched.
   * `-L --files-without-matches`:
     Only print filenames that don't contain matches.
+  * `--list-file-types`:
+    See `FILE TYPES` below.
   * `-m --max-count NUM`:
     Skip the rest of a file after NUM matches. Default is 10,000.
   * `--no-numbers`:            
@@ -87,6 +89,10 @@ Recursively search for PATTERN in PATH. Like grep or ack, but faster.
   * `-w --word-regexp`:
     Only match whole words.
 
+## FILE TYPES
+
+It is possible to restrict the types of files searched. For example, passing `--html` as the `file-types` parameter will search only files with the extensions `htm`, `html`, `shtml` or `xhtml`. For a list of supported `file-types` run `ag --list-file-types`.
+
 ## IGNORING FILES
 
 By default, ag will ignore files matched by patterns in .gitignore, .hgignore, or .agignore. These files can be anywhere in the directories being searched. Ag also ignores files matched by the svn:ignore property in subversion repositories. Finally, ag looks in $HOME/.agignore for ignore patterns. Binary files are ignored by default as well.

doc/generate_man.sh

@@ -34,8 +34,9 @@ BEGIN{
     } else if (first_4_chars == "    ") { # we are in a description line
       printf("      %s\n", substr($0, 5));
       first_item_in_list_of_options = 1;
-    } else if (first_4_chars == "## I") { # reached the end of #OPTIONS part
+    } else if (first_4_chars == "## F") { # reached the end of #OPTIONS part
       in_options_block = 0;
+      print $0;
     } else {
       print $0;
     }

src/options.c

@@ -22,7 +22,7 @@ const char *color_path = "\033[1;32m";        /* bold green */
 /* TODO: try to obey out_fd? */
 void usage(void) {
     printf("\n");
-    printf("Usage: ag [OPTIONS] PATTERN [PATH]\n\n");
+    printf("Usage: ag [FILE-TYPE] [OPTIONS] PATTERN [PATH]\n\n");
 
     printf("  Recursively search for PATTERN in PATH.\n");
     printf("  Like grep or ack, but faster.\n\n");
@@ -83,6 +83,13 @@ Search Options:\n\
   -w --word-regexp        Only match whole words\n\
   -z --search-zip         Search contents of compressed (e.g., gzip) files\n\
 \n");
+    printf("File Types:\n\
+The search can be restricted to certain types of files. Example:\n\
+  ag --html needle\n\
+  - Searches for 'needle' in files with suffix .htm, .html, .shtml or .xhtml.\n\
+\n\
+For a list of supported file types run:\n\
+  ag --list-file-types\n\n");
 }
 
 void print_version(void) {
@@ -146,6 +153,7 @@ void parse_options(int argc, char **argv, char **base_paths[], char **paths[]) {
     int group = 1;
     int help = 0;
     int version = 0;
+    int list_file_types = 0;
     int opt_index = 0;
     const char *home_dir = getenv("HOME");
     char *ignore_file_path = NULL;
@@ -189,6 +197,7 @@ void parse_options(int argc, char **argv, char **base_paths[], char **paths[]) {
         { "ignore-case", no_argument, NULL, 'i' },
         { "invert-match", no_argument, &opts.invert_match, 1 },
         { "line-numbers", no_argument, &opts.print_line_numbers, 2 },
+        { "list-file-types", no_argument, &list_file_types, 1 },
         { "literal", no_argument, NULL, 'Q' },
         { "match", no_argument, &useless, 0 },
         { "max-count", required_argument, NULL, 'm' },
@@ -443,6 +452,20 @@ void parse_options(int argc, char **argv, char **base_paths[], char **paths[]) {
         exit(0);
     }
 
+    if (list_file_types) {
+        int i;
+        printf("The following file types are supported:\n");
+        for (i = 0; i < LANG_COUNT; i++) {
+            printf("  --%s\n    ", langs[i].name);
+            int j;
+            for (j = 0; j < MAX_EXTENSIONS && langs[i].extensions[j]; j++) {
+                printf("  .%s", langs[i].extensions[j]);
+            }
+            printf("\n\n");
+        }
+        exit(0);
+    }
+
     if (needs_query && argc == 0) {
         log_err("What do you want to search for?");
         exit(1);