add echo and pritnf

1 files changed, 103 insertions, 0 deletions

diff --git a/src/commands/echo.c b/src/commands/echo.c
new file mode 100644
index 0000000..b80f872
--- /dev/null
+++ b/src/commands/echo.c
@@ -0,0 +1,103 @@
+#include "../command.h"
+
+#include <stdio.h>
+#include <string.h>
+
+static void print_with_escape_codes(const char* str) {
+    
+    size_t index = 0;
+    while (true) {
+        char c = str[index];
+        index++;
+
+        if (c == '\0') break;
+        if (c != '\\') {
+            putchar(c);
+            continue;
+        }
+
+        char n = str[index];
+        index++;
+
+        switch (n) {
+            case '\\':
+                putchar('\\');
+                break;
+            case 'b':
+                putchar('\b');
+                break;
+            case 'c':
+                exit(EXIT_SUCCESS);
+            case 'n':
+                putchar('\n');
+                break;
+            case 'r':
+                putchar('\r');
+                break;
+            case 't':
+                putchar('\t');
+                break;
+            case 'v':
+                putchar('\v');
+                break;
+            default:
+                putchar(c);
+                putchar(n);
+        }
+    }
+}
+
+COMMAND(echo) {
+
+    if (argc < 1) {
+        return EXIT_SUCCESS;
+    }
+
+    bool escape_codes = false;
+    bool newline = true;
+
+    int start = 0;
+
+    if (prefix("-", argv[0])) {
+
+        start = 1;
+
+        for (size_t i = 0; i < strlen(argv[0] + 1); i++) {
+            char c = argv[0][i + 1];
+            switch (c) {
+                case 'e':
+                    escape_codes = true;
+                    break;
+                case 'E':
+                    escape_codes = false;
+                    break;
+                case 'n':
+                    newline = false;
+                    break;
+                default:
+                    escape_codes = false;
+                    newline = true;
+                    start = 0;
+                    break;
+            }
+        }
+    }
+
+    for (int i = start; i < argc; i++) {
+         if (escape_codes) {
+            print_with_escape_codes(argv[i]);
+        } else {
+            printf("%s", argv[i]);
+        }
+
+        if (i + 1 != argc) {
+            putchar(' ');
+        }
+    } 
+
+    if (newline) {
+        putchar('\n');
+    }
+
+    return EXIT_SUCCESS;
+}