Changed libc structure, shouldn't've added anything new

2024-10-19 15:11:00 +02:00
parent e2e24d3853
commit 64b4e47d73
38 changed files with 264 additions and 276 deletions
@@ -0,0 +1,129 @@
+#include <syscall.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+// Warning: returns an allocated buffer, must be freed!
+char* _format(const char* fmt, va_list args) {
+    static char* buffer;
+    size_t len = 0;
+    size_t max = 256;
+
+    buffer = malloc(max);
+
+    size_t i = 0;
+    while (fmt[i] != '\0') {
+        if (len > max) {
+            max *= 2;
+            // Reallocate a larger buffer
+            char* temp = malloc(max);
+            strcpy(temp, buffer);
+            free(buffer);
+            buffer = temp;
+        }
+
+        // Formatting magic...
+        if (fmt[i] == '%') { i++;
+            /* TODO:
+             %p - pointer (0x########)
+             %n - ""
+             */
+            int pad = -1;
+            char padc = ' ';
+
+            if (fmt[i] == '0') { i++; padc = '0'; }
+            if (fmt[i] >= '0' && fmt[i] <= '9') {
+                pad = atoi(fmt + i);
+                while (fmt[i] >= '0' && fmt[i] <= '9') { i++; }
+            }
+            while (pad > 0) { buffer[len++] = padc; pad--; }
+
+            char c = fmt[i++];
+            if (c == 'd' || c == 'x' || c == 'o') {
+                int base = 10;
+                if (c == 'x') base = 16;
+                else if (c == 'o') base = 8;
+                
+                char* s = itoa(va_arg(args, int), base);
+                if (pad == 0) len -= strlen(s);
+                while ((buffer[len++] = *s++) != '\0');
+                len--;
+            } else if (c == 'c') {
+                if (pad == 0) len--;
+                buffer[len++] = va_arg(args, char);
+            } else if (c == 's') {
+                char* s = va_arg(args, char*);
+                if (pad == 0) len -= strlen(s);
+                while ((buffer[len++] = *s++) != '\0');
+                len--;
+            } else if (c == '%') {
+                buffer[len++] = '%';
+            } else {
+                buffer[len++] = '%';
+                if (padc == '0') { buffer[len++] = '0'; }
+                if (pad > 0) { buffer[len++] = '#'; } // TODO
+                buffer[len++] = c;
+            }
+        } else { buffer[len++] = fmt[i++]; }
+    }
+    
+    buffer[len] = '\0';
+    return buffer;
+}
+
+int sprintf(char* str, const char* fmt, ...) {
+    va_list args;
+    va_start(args, fmt);
+
+    char* buffer = _format(fmt, args);
+    strcpy(str, buffer);
+    free(buffer);
+    va_end(args);
+
+    return strlen(str);
+}
+
+int snprintf(char* str, size_t n, const char* fmt, ...) {
+    va_list args;
+    va_start(args, fmt);
+
+    char* buffer = _format(fmt, args);
+    strncpy(str, buffer, n);
+    free(buffer);
+    va_end(args);
+
+    return strlen(str);
+}
+
+int fprintf(FILE* stream, const char* fmt, ...) {
+    va_list args;
+    va_start(args, fmt);
+
+    char* buffer = _format(fmt, args);
+    size_t len = strlen(buffer);
+    write(stream->_file, buffer, len); // TODO: use fwrite()
+    
+    free(buffer);
+    va_end(args);
+    return len;
+}
+
+int printf(const char* fmt, ...) {
+    va_list args;
+    va_start(args, fmt);
+
+    char* buffer = _format(fmt, args);
+    size_t len = strlen(buffer);
+    write(stdout->_file, buffer, len); // TODO: use fwrite()
+    
+    free(buffer);
+    va_end(args);
+    return len;
+}
+
+void print(const char* s) {
+    write(1, s, strlen(s));
+}
+