From f0988a8a83142786295136d2a029c9eeb0f7d54e Mon Sep 17 00:00:00 2001
From: Shav Kinderlehrer <shav@trinket.icu>
Date: Sat, 29 Apr 2023 15:42:42 -0400
Subject: [PATCH] Start implementing -e

- extensions
---
 include/arg.h |  1 +
 src/lib/arg.c | 33 +++++++++++++++++++--------------
 src/main.c    | 20 +++++++++++++++-----
 3 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/include/arg.h b/include/arg.h
index 6782ef5..a1864c7 100644
--- a/include/arg.h
+++ b/include/arg.h
@@ -14,6 +14,7 @@ struct config {
   bool literal;
   bool pager;
   char *name;
+  char *extension;
   bool has_read_stdin;
 };
 
diff --git a/src/lib/arg.c b/src/lib/arg.c
index 3634831..030d453 100644
--- a/src/lib/arg.c
+++ b/src/lib/arg.c
@@ -1,13 +1,13 @@
 #include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdnoreturn.h>
+#include <unistd.h>
 
 #include "arg.h"
 #include "util.h"
 
-#define LAT_SHORT_ARGS "cltbrpn:Vh"
-#define LAT_USAGE "usage: lat [-cltbrpnVh] [file...]"
+#define LAT_SHORT_ARGS "cltbrpn:e:Vh"
+#define LAT_USAGE "usage: lat [-cltbrpneVh] [file...]"
 
 struct config conf;
 
@@ -16,17 +16,19 @@ void help(void) {
          "embellishments\n\n");
 
   printf("%s\n\n", LAT_USAGE);
-  printf(
-      "options:\n"
-      "\t-c\t\t toggle color\n"
-      "\t-l\t\t toggle line numbers\n"
-      "\t-t\t\t toggle file info headers\n"
-      "\t-b\t\t set binary mode, -b forces binary and -bb forces NOT binary\n"
-      "\t-r\t\t print everything (headers, line numbers, etc.) to stdout (or equivalent)\n"
-      "\t-p\t\t print file with the pager (uses less)\n"
-      "\t-n <name>\t\t manually set the name of the file in the title\n"
-      "\t-V\t\t show program version\n"
-      "\t-h\t\t display this help text\n\n");
+  printf("options:\n"
+         "\t-c           toggle color\n"
+         "\t-l           toggle line numbers\n"
+         "\t-t           toggle file info headers\n"
+         "\t-b           set binary mode, -b forces binary and -bb forces NOT "
+         "binary\n"
+         "\t-r           print everything (headers, line numbers, etc.) to "
+         "stdout (or equivalent)\n"
+         "\t-p           print file with the pager (uses less)\n"
+         "\t-n <name>    manually set the name of the file shown in the title\n"
+         "\t-e <program> link extension to lat\n"
+         "\t-V           show program version\n"
+         "\t-h           display this help text\n\n");
   printf("environment:\n"
          "\tNO_COLOR, see https://no-color.org/\n");
 }
@@ -69,6 +71,9 @@ int parseargs(int argc, char *argv[]) {
     case 'n':
       conf.name = optarg;
       break;
+    case 'e':
+      conf.extension = optarg;
+      break;
     case 'V':
       version();
       exit(EXIT_SUCCESS);
diff --git a/src/main.c b/src/main.c
index 4afabc8..781ab41 100644
--- a/src/main.c
+++ b/src/main.c
@@ -83,11 +83,14 @@ void run(FILE *fp, char *filename, bool tty) {
     int linecount = 1;
     for (int i = 0; i < f.lc; i++) {
       if (conf.lines) {
-        char *padding = linepad(linecount, f.lc);
-        fprintf(st, "%s%s%d│%s ", c.grey, padding, i + 1, c.reset);
+        { // line numbers
+          char *padding = linepad(linecount, f.lc);
+          fprintf(err, "%s%s%d│%s ", c.grey, padding, i + 1, c.reset);
+          free(padding);
+        }
+
         fwrite(f.lines[i].buf, 1, f.lines[i].len, st);
         fprintf(st, "\n");
-        free(padding);
         linecount++;
       } else {
         fprintf(st, "%s\n", f.lines[i].buf);
@@ -97,7 +100,8 @@ void run(FILE *fp, char *filename, bool tty) {
   } else {
     fwrite(f.buf, 1, f.buflen, st);
     fflush(st);
-    fwrite("\n", 1, 1, err);
+    if (tty)
+      fwrite("\n", 1, 1, err);
   }
   free(f.buf);
   free(f.lines);
@@ -127,6 +131,7 @@ void initconf(void) {
   conf.lines = true;
 
   conf.name = NULL;
+  conf.extension = NULL;
 }
 
 void clearstdin(void) {
@@ -150,8 +155,13 @@ int main(int argc, char *argv[]) {
 
   bool tty = isatty(STDOUT_FILENO);
 
+  int offset = parseargs(argc, argv);
+
+  conf.headers = conf.headers && tty;
+
+  printf("set extension to '%s'\n", conf.extension);
+
   if (argc > 1) {
-    int offset = parseargs(argc, argv);
 
     tty = tty || conf.literal;