file preview infrastructure & implementation of preview of text files

config.h

@@ -0,0 +1,7 @@
+#include "defines.h"
+
+
+static file_preview file_previews[] = {
+	{ "c", "&a" },
+	{ ".c", "&ueberzug" },
+};

defines.h

@@ -1,3 +1,8 @@
+#ifndef CONFIG_GUARD
+#define CONFIG_GUARD
+#include "config.h" 
+#endif
+
 #define STATUS_QUIT_PROGRAM 1
 #define STATUS_RUN_BACKEND 2
 #define STATUS_RELOAD_DIRECTORY 4
@@ -21,6 +26,7 @@
 #define FILE_STATUS_HOVER 1
 #define FILE_STATUS_SELECTED 2;
 #define FILE_STATUS_IS_REGULAR_FILE 4
+#define FILE_STATUS_FILE_OPEN 128 /* only used for file previews */
 
 #define COLOR_UNKNOWN 0
 #define COLOR_DIR 1
@@ -44,9 +50,10 @@
 #define FILE_TYPE_SOCK COLOR_SOCK
 #define FILE_TYPE_FIFO COLOR_FIFO
 #define FILE_TYPE_ORPHAN COLOR_ORPHAN
+#define FILE_TYPE_OPEN_FILE 128 /* this is only used in rgt_content to print a file preview, not the dir */
 
-#ifndef GUARD
+#ifndef STRUCT_GUARD
-#define GUARD
+#define STRUCT_GUARD
 
 /* complex types are good actually */
 typedef struct File {
@@ -61,5 +68,11 @@ typedef struct Color {
 	char *file_extension;
 	short color_pair;
 } color;
+typedef struct File_preview {
+	char *file_extension;
+	char *command; /* this will blindly execute any inserted shell command */
+			/* commands with an '&' prefix are inbuild */
+} file_preview;
+	
 
 #endif

threading.c

@@ -4,8 +4,10 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <time.h>
 #include "defines.h"
 #include "backend.h"
+#include "file_previews.h"
 
 
 pthread_mutex_t mutex_top;
@@ -18,6 +20,7 @@ pthread_mutex_t mutex_selection;
 file *rgt_content;
 file *mid_content;
 file *lft_content;
+char *rgt_buffer; /* used for file previews, unlike rgt_content, which is used for directory previews */
 
 char *top_content; /* current path */
 
@@ -26,12 +29,15 @@ unsigned long mid_file_count;
 unsigned long lft_file_count;
 unsigned long top_width;
 
+extern file_preview file_previews[];
 	
 
 extern unsigned int status;
 extern unsigned long selected_file_current;
 extern unsigned long selected_file_last;
 
+void *thread_rgt(void *data);
+
 void *thread_mid(void *data){
 	pthread_mutex_lock(&mutex_mid);
 
@@ -39,8 +45,8 @@ void *thread_mid(void *data){
 	char *path;
 	if((path=getcwd(NULL, 0)) == NULL) {
 		mid_content = malloc(sizeof(file));
-		mid_content[1].file_name_width = sizeof("cannot open directory");
+		mid_content[0].file_name_width = sizeof("cannot open directory");
-		mid_content[1].file_name = "cannot open directory";
+		mid_content[0].file_name = "cannot open directory";
 		mid_file_count = 1;
 	} else {
 
@@ -78,8 +84,8 @@ void *thread_lft(void *data){
 	char *path;
 	if((path=getcwd(NULL, 0)) == NULL) {
 		lft_content = malloc(sizeof(file));
-		lft_content[1].file_name_width = sizeof("cannot open directory");
+		lft_content[0].file_name_width = sizeof("cannot open directory");
-		lft_content[1].file_name = "cannot open directory";
+		lft_content[0].file_name = "cannot open directory";
 		lft_file_count = 1;
 	} else {
 
@@ -105,32 +111,41 @@ void *thread_rgt(void *data){
 	pthread_mutex_lock(&mutex_rgt);
 
 	pthread_mutex_lock(&mutex_mid);
-	char *path = mid_content[selected_file_current].file_name;
+	/* TODO(2025-06-13T01:24:43) fix the occasional wrongly coppied path */
+	char *path = malloc(mid_content[selected_file_current].file_name_width);
+	strcpy(path, mid_content[selected_file_current].file_name);
+	unsigned long name_len = strlen(mid_content[selected_file_current].file_name);
+	unsigned long file_size = mid_content[selected_file_current].file_size_bytes;
+	unsigned char file_type = mid_content[selected_file_current].file_type;
+
 	pthread_mutex_unlock(&mutex_mid);
 
-	if (mid_content[selected_file_current].file_type == FILE_TYPE_DIR || mid_content[selected_file_current].file_type == FILE_TYPE_SYMLINK) {
+	if (file_type == FILE_TYPE_DIR || file_type == FILE_TYPE_SYMLINK) {
 		free(rgt_content);
-		rgt_file_count = (unsigned long)get_dir_size(path);
+		rgt_file_count = get_dir_size(path);
 		rgt_content = malloc(rgt_file_count * sizeof(file));
 		memset(rgt_content, ' ', rgt_file_count * sizeof(file));
 		get_dir_content(path, &rgt_file_count, rgt_content);
-	} else if (mid_content[selected_file_current].file_type == FILE_TYPE_REGULAR) {
+		rgt_content[0].status &= ~FILE_STATUS_FILE_OPEN;
-		FILE *fp = fopen(mid_content[selected_file_current].file_name, "r");
+	} else if (file_type == FILE_TYPE_REGULAR || file_type == FILE_TYPE_EXEC) {
-		unsigned long file_size = ftell(fp);
-		rewind(fp);
 		free(rgt_content);
+
 		rgt_content = malloc(sizeof(file));
-		rgt_content[0].file_name = malloc(file_size);
+		rgt_content[0].file_name = malloc(name_len);
-		fgets(rgt_content[0].file_name, file_size, fp);
+		rgt_content[0].file_name_width = name_len;
 		rgt_content[0].file_size_bytes = file_size;
-		rgt_content[0].file_type = FILE_TYPE_REGULAR;
+		/*memcpy(rgt_content[0].file_name, path, sizeof(path)/sizeof(char));*/
-		rgt_content[0].file_name_width = file_size;
+		strcpy(rgt_content[0].file_name, path);
-		rgt_content[0].color_pair = 0;
+		rgt_file_count = 1;
-		rgt_content[0].status = 0;
+
-		fclose(fp);
+		if (file_type != FILE_TYPE_EXEC) {
+			rgt_content[0].file_type = FILE_TYPE_OPEN_FILE;
+			rgt_content[0].status = FILE_STATUS_HOVER;
+			free(rgt_buffer);
+			rgt_buffer = preview_file(rgt_content[0].file_name, file_size);
 		}
 
-
+	}
 
 	pthread_mutex_unlock(&mutex_rgt);
 	pthread_exit(NULL);
@@ -159,11 +174,12 @@ void *thread_btm(void *data){
 }
 
 void threading_init(){
-	rgt_content = malloc(sizeof(char));
+	rgt_content = malloc(sizeof(file));
 	mid_content = malloc(sizeof(file));
 	lft_content = malloc(sizeof(file));
 
 	top_content = malloc(sizeof(char));
+	rgt_buffer = malloc(sizeof(char));
 
 	pthread_mutex_init(&mutex_top, NULL);
 	pthread_mutex_init(&mutex_mid, NULL);

window.c

@@ -1,5 +1,6 @@
 #include <curses.h>
 #include <pthread.h>
+#include <unistd.h>
 #include "defines.h"
 
 extern unsigned int status;
@@ -12,6 +13,7 @@ extern file *mid_content;
 extern file *lft_content;
 extern file *rgt_content;
 extern char *top_content;
+extern char *rgt_buffer;
 
 extern unsigned long lft_file_count;
 extern unsigned long mid_file_count;
@@ -31,6 +33,7 @@ void window_top(WINDOW *win){
 	if (pthread_mutex_trylock(&mutex_top)) {
 		wprintw(win,"loading"); 
 		status |= STATUS_UPDATE_SCREEN_0;
+		pthread_mutex_unlock(&mutex_rgt);
 
 	} else {
 		wattron(win, COLOR_PAIR(COLOR_PATH));
@@ -42,6 +45,7 @@ void window_top(WINDOW *win){
 void window_btm(WINDOW *win){
 	werase(win);
 	if (pthread_mutex_trylock(&mutex_btm)) {
+		pthread_mutex_unlock(&mutex_rgt);
 	} else {
 		pthread_mutex_unlock(&mutex_btm);
 	}
@@ -56,6 +60,7 @@ void window_lft(WINDOW *win){
 	if (pthread_mutex_trylock(&mutex_lft)) {
 		mvwprintw(win, local_height/2, local_width/2, "LOADING"); 
 		status |= STATUS_UPDATE_SCREEN_0;
+		pthread_mutex_unlock(&mutex_rgt);
 
 	} else {
 		print_dir(win, &lft_file_count, lft_content);
@@ -72,6 +77,7 @@ void window_mid(WINDOW *win){
 	if (pthread_mutex_trylock(&mutex_mid)) {
 		mvwprintw(win, local_height/2, local_width/2, "LOADING"); 
 		status |= STATUS_UPDATE_SCREEN_0;
+		pthread_mutex_unlock(&mutex_rgt);
 
 	} else {
 		print_dir(win, &mid_file_count, mid_content);
@@ -86,10 +92,16 @@ void window_rgt(WINDOW *win){
 	unsigned long local_height;
 	getmaxyx(win, local_height, local_width);
 	if (pthread_mutex_trylock(&mutex_rgt)) {
+		/* TODO(2025-06-13T00:49:26) fix race condition and use trylock */
 		mvwprintw(win, local_height/2, local_width/2, "LOADING"); 
 		status |= STATUS_UPDATE_SCREEN_0;
+		pthread_mutex_unlock(&mutex_rgt);
+	} else {
+		if (rgt_content[0].file_type == FILE_TYPE_OPEN_FILE) {
+			mvwprintw(win, 0, 0, "%s", rgt_buffer);
 		} else {
 			print_dir(win, &rgt_file_count, rgt_content);
+		}
 		pthread_mutex_unlock(&mutex_rgt);
 	}
 }