Create cmd to generate man pages for prof commands

`profanity mangen` will create for each command (`/account`, `/roster`)
an own manpage (`profanity-account.1`, `profanity-roster.1`)

See https://github.com/profanity-im/profanity/issues/1444

Needs some polishing formatting wise.

RELEASE_GUIDE.md

@@ -15,6 +15,10 @@ Usually release candidates are tagged 0.6.0.rc1, 0.6.0.rc2 and tested for a week
 * Generate HTML docs (the docgen argument only works when package status is development)
     `./profanity docgen`
 
+* Generate manpages for profanity commands (the mangen argument only works when package status is development)
+    `./profanity mangen`
+  These files should be added to the docs subfolder and added to git whenever a command changes.
+
 * Determine if libprofanitys version needs to be [increased](https://github.com/profanity-im/profanity/issues/973)
 * Update plugin API docs (./apidocs/c and ./apidocs/python) need to run the `gen.sh` and commit the results to the website git repo
 * Update CHANGELOG

src/command/cmd_defs.c

@@ -2833,3 +2833,70 @@ command_docgen(void)
     printf("\nProcessed %d commands.\n\n", g_list_length(cmds));
     g_list_free(cmds);
 }
+
+void
+command_mangen(void)
+{
+    GList* cmds = NULL;
+
+    for (unsigned int i = 0; i < ARRAY_SIZE(command_defs); i++) {
+        Command* pcmd = command_defs + i;
+        cmds = g_list_insert_sorted(cmds, pcmd, (GCompareFunc)_cmp_command);
+    }
+
+    mkdir_recursive("docs");
+
+    GList* curr = cmds;
+    while (curr) {
+        Command* pcmd = curr->data;
+
+        char* filename = NULL;
+        if (asprintf(&filename, "docs/profanity-%s.1", &pcmd->cmd[1]) == -1) {
+            // TODO: error
+            return;
+        }
+        FILE* manpage = fopen(filename, "w");
+        free(filename);
+
+        fputs(".TH man 1 \"2020-07-01\" \""PACKAGE_VERSION"\" \"Profanity XMPP client\"\n", manpage);
+        fputs(".SH NAME\n", manpage);
+        fprintf(manpage, "%s\n", pcmd->cmd);
+
+        fputs("\n.SH DESCRIPTION\n", manpage);
+        fprintf(manpage, "%s\n", pcmd->help.desc);
+
+        fputs("\n.SH SYNOPSIS\n", manpage);
+        int i = 0;
+        while (pcmd->help.synopsis[i]) {
+            fprintf(manpage, "%s\n", pcmd->help.synopsis[i]);
+            fputs("\n.BR\n", manpage);
+            i++;
+        }
+
+        if (pcmd->help.args[0][0] != NULL) {
+            fputs("\n.SH ARGUMENTS\n", manpage);
+            for (i = 0; pcmd->help.args[i][0] != NULL; i++) {
+                fprintf(manpage, "%s\n", pcmd->help.args[i][0]);
+                fprintf(manpage, "%s\n", pcmd->help.args[i][1]);
+                fputs("\n.BR\n", manpage);
+            }
+        }
+
+        if (pcmd->help.examples[0] != NULL) {
+            fputs("\n.SH EXAMPLES\n", manpage);
+            int i = 0;
+            while (pcmd->help.examples[i]) {
+                fprintf(manpage, "%s\n", pcmd->help.examples[i]);
+                fputs("\n.BR\n", manpage);
+                i++;
+            }
+        }
+
+        curr = g_list_next(curr);
+
+        fclose(manpage);
+    }
+
+    printf("\nProcessed %d commands.\n\n", g_list_length(cmds));
+    g_list_free(cmds);
+}

src/command/cmd_defs.h

@@ -50,6 +50,7 @@ GList* cmd_get_ordered(const char* const tag);
 gboolean cmd_valid_tag(const char* const str);
 
 void command_docgen(void);
+void command_mangen(void);
 
 GList* cmd_search_index_all(char* term);
 GList* cmd_search_index_any(char* term);

src/main.c

@@ -69,9 +69,14 @@ static char* theme_name = NULL;
 int
 main(int argc, char** argv)
 {
-    if (argc == 2 && g_strcmp0(argv[1], "docgen") == 0 && g_strcmp0(PACKAGE_STATUS, "development") == 0) {
+    if (argc == 2  && g_strcmp0(PACKAGE_STATUS, "development") == 0) {
+        if (g_strcmp0(argv[1], "docgen") == 0) {
             command_docgen();
             return 0;
+        } else if (g_strcmp0(argv[1], "mangen") == 0) {
+            command_mangen();
+            return 0;
+        }
     }
 
     static GOptionEntry entries[] = {