Add 'cat' subcommand

This command outputs a raw message matched by search term to the
standard output. It allows MUAs to access the messages for piping,
attachment manipulation, etc. by running notmuch cat rather then
directly access the file. This will simplify the MUAs when they need
to operate on a remote database.

Edited-by: Carl Worth <cworth@cworth.org>: Remove trailing whitespace,
add missing "test_done" to new test script to avoid "Unexpected exit"
error.

notmuch-client.h

@@ -110,6 +110,9 @@ notmuch_tag_command (void *ctx, int argc, char *argv[]);
 int
 notmuch_search_tags_command (void *ctx, int argc, char *argv[]);
 
+int
+notmuch_cat_command (void *ctx, int argc, char *argv[]);
+
 int
 notmuch_part_command (void *ctx, int argc, char *argv[]);
 

notmuch-show.c

@@ -631,6 +631,89 @@ notmuch_show_command (void *ctx, unused (int argc), unused (char *argv[]))
     return 0;
 }
 
+int
+notmuch_cat_command (void *ctx, unused (int argc), unused (char *argv[]))
+{
+    notmuch_config_t *config;
+    notmuch_database_t *notmuch;
+    notmuch_query_t *query;
+    notmuch_messages_t *messages;
+    notmuch_message_t *message;
+    char *query_string;
+    int i;
+    const char *filename;
+    FILE *file;
+    size_t size;
+    char buf[4096];
+
+    for (i = 0; i < argc && argv[i][0] == '-'; i++) {
+	fprintf (stderr, "Unrecognized option: %s\n", argv[i]);
+	return 1;
+    }
+
+    config = notmuch_config_open (ctx, NULL, NULL);
+    if (config == NULL)
+	return 1;
+
+    query_string = query_string_from_args (ctx, argc, argv);
+    if (query_string == NULL) {
+	fprintf (stderr, "Out of memory\n");
+	return 1;
+    }
+
+    if (*query_string == '\0') {
+	fprintf (stderr, "Error: notmuch cat requires at least one search term.\n");
+	return 1;
+    }
+
+    notmuch = notmuch_database_open (notmuch_config_get_database_path (config),
+				     NOTMUCH_DATABASE_MODE_READ_ONLY);
+    if (notmuch == NULL)
+	return 1;
+
+    query = notmuch_query_create (notmuch, query_string);
+    if (query == NULL) {
+	fprintf (stderr, "Error: Out of memory\n");
+	return 1;
+    }
+
+    if (notmuch_query_count_messages (query) != 1) {
+	fprintf (stderr, "Error: search term did not match precisely one message.\n");
+	return 1;
+    }
+
+    messages = notmuch_query_search_messages (query);
+    message = notmuch_messages_get (messages);
+
+    if (message == NULL) {
+	fprintf (stderr, "Error: Cannot find matching message.\n");
+	return 1;
+    }
+
+    filename = notmuch_message_get_filename (message);
+    if (filename == NULL) {
+	fprintf (stderr, "Error: Cannot message filename.\n");
+	return 1;
+    }
+
+    file = fopen (filename, "r");
+    if (file == NULL) {
+	fprintf (stderr, "Error: Cannot open file %s: %s\n", filename, strerror (errno));
+	return 1;
+    }
+
+    while (!feof (file)) {
+	size = fread (buf, 1, sizeof (buf), file);
+	fwrite (buf, size, 1, stdout);
+    }
+
+    fclose (file);
+    notmuch_query_destroy (query);
+    notmuch_database_close (notmuch);
+
+    return 0;
+}
+
 int
 notmuch_part_command (void *ctx, unused (int argc), unused (char *argv[]))
 {

notmuch.1

@@ -300,6 +300,10 @@ See the
 section below for details of the supported syntax for <search-terms>.
 .RE
 .TP
+.BR cat  " <search-term>..."
+
+Output raw content of a single message matched by the search term.
+.TP
 .BR count " <search-term>..."
 
 Count messages matching the search terms.

notmuch.c

@@ -343,6 +343,10 @@ command_t commands[] = {
       "\tcontain tags only from messages that match the search-term(s).\n"
       "\n"
       "\tIn both cases the list will be alphabetically sorted." },
+    { "cat", notmuch_cat_command,
+      "<search-terms>",
+      "Output raw content of a single message matched by the search term.",
+      "" },
     { "part", notmuch_part_command,
       "--part=<num> <search-terms>",
       "Output a single MIME part of a message.",

test/cat

@@ -0,0 +1,40 @@
+#!/bin/bash
+
+test_description='notmuch cat'
+. ./test-lib.sh
+
+test_begin_subtest "Generate some messages"
+generate_message
+generate_message
+output=$(NOTMUCH_NEW)
+test_expect_equal "$output" "Added 2 new messages to the database."
+
+test_begin_subtest "Without arguments"
+output=$(notmuch cat 2>&1)
+test_expect_equal "$output" "Error: notmuch cat requires at least one search term."
+
+test_begin_subtest "Attempt to cat multiple messages"
+output=$(notmuch cat "*" 2>&1)
+test_expect_equal "$output" "Error: search term did not match precisely one message."
+
+test_begin_subtest "Cat a message"
+output=$(notmuch cat id:msg-001@notmuch-test-suite)
+test_expect_equal "$output" "From: Notmuch Test Suite <test_suite@notmuchmail.org>
+To: Notmuch Test Suite <test_suite@notmuchmail.org>
+Message-Id: <msg-001@notmuch-test-suite>
+Subject: Test message #1
+Date: Tue, 05 Jan 2001 15:43:57 -0000
+
+This is just a test message (#1)"
+
+test_begin_subtest "Cat another message"
+output=$(notmuch cat id:msg-002@notmuch-test-suite)
+test_expect_equal "$output" "From: Notmuch Test Suite <test_suite@notmuchmail.org>
+To: Notmuch Test Suite <test_suite@notmuchmail.org>
+Message-Id: <msg-002@notmuch-test-suite>
+Subject: Test message #2
+Date: Tue, 05 Jan 2001 15:43:57 -0000
+
+This is just a test message (#2)"
+
+test_done

test/notmuch-test

@@ -16,7 +16,7 @@ fi
 
 cd $(dirname "$0")
 
-TESTS="basic new search json thread-naming reply dump-restore uuencode thread-order author-order from-guessing long-id encoding emacs"
+TESTS="basic new search json thread-naming reply cat dump-restore uuencode thread-order author-order from-guessing long-id encoding emacs"
 
 # Clean up any results from a previous run
 rm -r test-results >/dev/null 2>/dev/null