From f3d03e71ede8e94e7137777ab5ad5570c3d11b31 Mon Sep 17 00:00:00 2001
From: iceyrazor <iceyrazor@mailfence.com>
Date: Fri, 6 Mar 2026 22:34:50 -0600
Subject: some cleanup and shell var - SHELL is now set - cwd now has realloc -
 realloc with error checking is now a fucntion like malloce

---
 README.md              |  2 +-
 src/helper_functions.c | 11 ++++++++++-
 src/lsh_builtins.c     | 11 +++++++++--
 src/lsh_main_func.c    | 12 ++----------
 src/lsh_split_line.c   |  6 +-----
 src/main.c             | 23 +++++++++++++++++++++++
 6 files changed, 46 insertions(+), 19 deletions(-)

diff --git a/README.md b/README.md
index eb9a83e..bba5b3f 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ Going to try and make it mostly POSIX compliant.
 - [x] custom prompts
 - [x] minimal current directory
 - [x] handle ~
-- [ ] dynamically allocate cwd in cd builtin command
+- [x] dynamically allocate cwd in cd builtin command
 - [ ] history
 - [ ] cursor movement
 - [ ] tab to autocomplete files and dirs
diff --git a/src/helper_functions.c b/src/helper_functions.c
index 162cf45..cd35848 100644
--- a/src/helper_functions.c
+++ b/src/helper_functions.c
@@ -16,6 +16,15 @@ void *malloce(size_t size){
     return mal;
 }
 
+void *realloce(void* mal,size_t size){
+    mal=realloc(mal,size);
+    if(!mal){
+        fprintf(stderr, "lsh: allocation error\n");
+        exit(EXIT_FAILURE);
+    }
+    return mal;
+}
+
 char *pop(char *token, int ch_i){
     if(token[ch_i]=='\0'){
         return token;
@@ -83,7 +92,7 @@ char *basename(char *path_in)
 {
     char *token = NULL;
     char *lastToken = NULL;
-    char *basePath;
+    char *basePath = NULL;
 
     basePath = (char *)malloce(sizeof(char) * (strlen(path_in) + 1));
     strcpy(basePath, path_in);
diff --git a/src/lsh_builtins.c b/src/lsh_builtins.c
index dda49c4..51a44cd 100644
--- a/src/lsh_builtins.c
+++ b/src/lsh_builtins.c
@@ -40,6 +40,7 @@ int lsh_num_builtins() {
 /*
    Builtin function implementations.
    */
+#define LSH_CWD_BUF_SIZE 1024;
 int lsh_cd(char **args)
 {
     if (args[1] == NULL) {
@@ -49,8 +50,14 @@ int lsh_cd(char **args)
         if (err != 0) {
             perror("lsh");
         }
-        char *cwd=(char*)malloce(sizeof(char)*4096);
-        getcwd(cwd,sizeof(char*)*4096);
+
+        int bufsize=LSH_CWD_BUF_SIZE;
+        char *cwd=(char*)malloce(sizeof(char)*bufsize+1);
+        while(getcwd(cwd,sizeof(char)*bufsize)==NULL){
+            bufsize += LSH_CWD_BUF_SIZE;
+            cwd=(char*)realloce(cwd,sizeof(char)*bufsize+1);
+        }
+
         setenv("PWD",cwd,1);
         free(cwd);
     }
diff --git a/src/lsh_main_func.c b/src/lsh_main_func.c
index 52c016b..ea2729d 100644
--- a/src/lsh_main_func.c
+++ b/src/lsh_main_func.c
@@ -36,11 +36,7 @@ char *lsh_read_line(void)
         // If we have exceeded the buffer, reallocate.
         if (position >= bufsize) {
             bufsize += LSH_RL_BUFSIZE;
-            buffer = realloc(buffer, bufsize);
-            if (!buffer) {
-                fprintf(stderr, "lsh: allocation error\n");
-                exit(EXIT_FAILURE);
-            }
+            buffer = realloce(buffer, bufsize);
         }
     }
 }
@@ -160,11 +156,7 @@ CMD **lsh_split_command(char *line)
 
         if (position * bufsize >= bufsize) {
             bufsize += sizeof(CMD*);
-            tokens = realloc(tokens, bufsize);
-            if (!tokens) {
-                fprintf(stderr, "lsh: allocation error\n");
-                exit(EXIT_FAILURE);
-            }
+            tokens = realloce(tokens, bufsize);
         }
 
         // do not make Redirect or Append a actual command to run
diff --git a/src/lsh_split_line.c b/src/lsh_split_line.c
index ff4f644..17e16a7 100644
--- a/src/lsh_split_line.c
+++ b/src/lsh_split_line.c
@@ -164,11 +164,7 @@ char **lsh_split_line(char *line)
 
         if (position >= bufsize) {
             bufsize += LSH_TOK_BUFSIZE;
-            tokens = realloc(tokens, bufsize * sizeof(char*));
-            if (!tokens) {
-                fprintf(stderr, "lsh: allocation error\n");
-                exit(EXIT_FAILURE);
-            }
+            tokens = realloce(tokens, bufsize * sizeof(char*));
         }
 
         token = strtok_quotes(NULL);
diff --git a/src/main.c b/src/main.c
index 427d316..ef88291 100755
--- a/src/main.c
+++ b/src/main.c
@@ -1,6 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <sys/param.h>
+#include <errno.h>
 
 #include "main.h"
 #include "helper_functions.c"
@@ -18,6 +20,11 @@ void lsh_loop(SHELL_OB *shell_obj){
         //get pwd
         char *cwd= getenv("PWD");
         char *pwd=basename(cwd);
+        if(pwd==NULL){
+            fprintf(stderr,"lsh:pwd is null\n\n");
+            exit(EXIT_FAILURE);
+        }
+
         snprintf(shell_obj->prompt,sizeof(char) * 1024,"%s %s> ",shell_obj->pre_prompt,pwd);
         free(pwd);
         printf("%s",shell_obj->prompt);
@@ -46,6 +53,18 @@ void lsh_loop(SHELL_OB *shell_obj){
     } while (status);
 }
 
+static char* call_realpath (char * argv0) {
+    char* resolved_path=(char*)malloce(sizeof(char)*PATH_MAX);
+
+    if (realpath (argv0, resolved_path) == 0) { 
+        fprintf (stderr, "lsh: realpath failed: %s\n", strerror (errno));
+        exit(errno);
+    }
+    else {
+        return resolved_path;
+    }
+}
+
 int main(int argc, char **argv){
     //set sh level
     char *shlvl = getenv("SHLVL");
@@ -56,6 +75,9 @@ int main(int argc, char **argv){
         setenv("SHLVL",shlvl,1);
     }
 
+    char* prog_path = call_realpath(argv[0]);
+    setenv("SHELL",prog_path,1);
+
     //Set The prompt
     SHELL_OB shell_obj;
     shell_obj.prompt = (char *)malloce(sizeof(char) * 1024);
@@ -73,5 +95,6 @@ int main(int argc, char **argv){
 
     free(shell_obj.prompt);
     free(shell_obj.pre_prompt);
+    free(prog_path);
     return EXIT_SUCCESS;
 }
-- 
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