From 7b542598af20d2ca853a0542307dcb13773f5769 Mon Sep 17 00:00:00 2001
From: Anonymus Raccoon <tr.tristan-roux@outlook.fr>
Date: Sun, 24 May 2020 22:51:49 +0200
Subject: [PATCH] Cleaning the parser

---
 src/parser/parser.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/parser/parser.c b/src/parser/parser.c
index 75f6d1e..10bd6ad 100644
--- a/src/parser/parser.c
+++ b/src/parser/parser.c
@@ -42,6 +42,7 @@ char **remove_leading_entries(char **cmds)
 char *process_aliases(char *cmd, env_t *env)
 {
     int bin_len;
+    int len;
 
     for (bin_len = 0; cmd[bin_len]; bin_len++) {
         if (cmd[bin_len] == ' ' || cmd[bin_len] == '\t')
@@ -49,10 +50,11 @@ char *process_aliases(char *cmd, env_t *env)
     }
     for (alias_t *al = env->alias; al; al = al->next) {
         if (!strncmp(al->alias, cmd, bin_len)) {
-            cmd = realloc(cmd, strlen(cmd) + strlen(al->command) + 1 - bin_len);
+            len = strlen(cmd) + strlen(al->command) + 1 - bin_len;
+            rm_n_char(cmd, bin_len);
+            cmd = realloc(cmd, len);
             if (!cmd)
                 return (NULL);
-            rm_n_char(cmd, bin_len);
             insert_substring(cmd, al->command, 1);
         }
     }
@@ -66,8 +68,17 @@ char **parse_input(char *cmd, env_t *env, wordexp_t *parser)
     if (!(cmd = process_vars(cmd, env)))
         return (NULL);
     cmd = process_aliases(cmd, env);
-    if (wordexp(cmd, parser, WRDE_SHOWERR)) {
-        perror(SHELL_NAME);
+    switch (wordexp(cmd, parser, WRDE_SHOWERR)) {
+    case 0:
+        break;
+    case WRDE_BADCHAR:
+        dprintf(2, "Illegal occurrence of one of |, &, ;, <, >, (, ), {, }.\n");
+        return (NULL);
+    case WRDE_SYNTAX:
+        dprintf(2, "Shell syntax error\n");
+        return (NULL);
+    default:
+        dprintf(2, "Unknonw parsing error.\n");
         return (NULL);
     }
     free(cmd);