From 7414651893472a7590aacb34370746ec6ce49762 Mon Sep 17 00:00:00 2001
From: Alessandro Mauri <alemauri001@gmail.com>
Date: Tue, 14 Sep 2021 19:00:19 +0200
Subject: [PATCH] bru h

---
 config.h |  3 ++-
 fstr.c   | 23 +++++++++++++++++++++++
 fstr.h   | 14 ++++++++++++++
 makefile |  8 ++++++++
 msh.c    | 55 ++++++++++++++++++++++++++++++++++++++++++++-----------
 5 files changed, 91 insertions(+), 12 deletions(-)
 create mode 100644 fstr.c
 create mode 100644 fstr.h
 create mode 100644 makefile

diff --git a/config.h b/config.h
index 3ebec85..0ddc3f0 100644
--- a/config.h
+++ b/config.h
@@ -4,5 +4,6 @@
 #define DEF_HISTSIZE 512
 #define DEF_HISTPATH ".history"
 #define DEF_SHELLRC ".mshrc"
+#define DEF_CHUNKSIZE 256
 
-#endif
\ No newline at end of file
+#endif
diff --git a/fstr.c b/fstr.c
new file mode 100644
index 0000000..0b9e3a8
--- /dev/null
+++ b/fstr.c
@@ -0,0 +1,23 @@
+#define _POSIX_C_SOURCE 200809l
+
+#include <stdlib.h>
+
+#include "fstr.h"
+#include "config.h"
+
+void fstr_add_space(fstr_t *fs)
+{
+	erealloc(fs->s, fs->len + fs->space + DEF_CHUNKSIZE + 1);
+	fs->space += DEF_CHUNKSIZE;
+}
+
+void fstr_append_char(fstr_t *fs, char c)
+{
+	if (!fs)
+		return;
+	if (fs->space < 1)
+		fstr_add_space(fs);
+	fs->s[fs->len++] = c;
+	fs->s[fs->len] = '\0';
+	fs->space--;
+}
diff --git a/fstr.h b/fstr.h
new file mode 100644
index 0000000..635b103
--- /dev/null
+++ b/fstr.h
@@ -0,0 +1,14 @@
+#ifndef _MSH_FSTR_H
+#define _MSH_FSTR_H
+
+// current length of the string and remaining space, total allocated space is
+// len + space
+typedef struct _fstr {
+	unsigned long int len;
+	unsigned long int space;
+	char *s;
+} fstr_t;
+
+void fstr_append_char(fstr_t *, char);
+
+#endif
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..769f902
--- /dev/null
+++ b/makefile
@@ -0,0 +1,8 @@
+.POSIX:
+
+CFLAGS = -Wall -Werror -pedantic -Wextra -std=c11
+
+msh: msh.c fstr.c
+
+clean:
+	rm -f msh *.o
diff --git a/msh.c b/msh.c
index 3419df1..374163a 100644
--- a/msh.c
+++ b/msh.c
@@ -1,7 +1,16 @@
+#define _POSIX_C_SOURCE 200809l
+
+#include <sys/types.h>
+
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <pwd.h>
 
-char *PS1 = NULL;
+#include "config.h"
+#include "fstr.h"
+
+fstr_t PS1 = {0};
 unsigned int histsize = DEF_HISTSIZE;
 
 // Buffered user data
@@ -10,19 +19,29 @@ struct {
 	char *home;
 	uid_t uid;
 	gid_t gid;
-} uinfo;
+} uinfo = {0};
+
+struct {
+	// $ or #
+	char tag;
+} shinfo;
 
-void sh_fill_uinfo(void);
+void sh_update_uinfo(void);
+void sh_update_shinfo(void);
 void sh_update_ps1(void);
 inline void sh_print_ps1(void);
 
 int main(int argc, char **argv)
 {
-	sh_fill_uinfo();
+	(void)argc;
+	(void)argv;
 
 	for (;;) {
+		sh_update_uinfo();
+		sh_update_shinfo();
 		sh_update_ps1();
 		sh_print_ps1();
+		for(;;);
 	}
 
 	return EXIT_SUCCESS;
@@ -30,19 +49,33 @@ int main(int argc, char **argv)
 
 void sh_fill_uinfo(void)
 {
-	struct pwuid pw;
-	uinfo.uid = getuid();
-	uidfo.gid = getgid();
+	struct passwd *pw;
+	uid_t nuid;
+	nuid = getuid();
+	if (nuid == uinfo.uid && uinfo.name)
+		return;
+	uinfo.uid = nuid;
+	pw = getpwuid(uinfo.uid);
+	// User not found
+	if (!pw)
+		exit(EXIT_FAILURE);
+	uinfo.gid = pw->pw_gid;
+	uinfo.name = estrdup(pw->pw_name);
+	uinfo.home = estrdup(pw->pw_dir);
+}
 
+void sh_update_shinfo(void)
+{
+	shinfo.tag = uinfo.uid ? '$' : '#';
 }
 
 inline void sh_print_ps1(void)
 {
-	puts(PS1);
-	putchar(' ');
+	puts(PS1.s);
 }
 
 void sh_update_ps1(void)
 {
-	
-}
\ No newline at end of file
+	fstr_append_char(&PS1, shinfo.tag);
+	fstr_append_char(&PS1, ' ');
+}