ejercicio de argchivos

c/files/files3/main.c

@@ -0,0 +1,85 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char *argv[]) {
+    if (argc < 2) {
+        fprintf(stderr, "Argumentos invalidos\n");
+        return 1;
+    }
+
+    char *fname;
+
+    fname = strdup(argv[1]);
+
+    if (fname == NULL) {
+        perror("strdup");
+        return 1;
+    }
+
+    FILE *pfile = fopen(fname, "rb");
+
+    if (pfile == NULL) {
+        perror("fopen");
+        fclose(pfile);
+        return 1;
+    }
+
+    uint8_t *header = NULL;
+
+    header = malloc(sizeof(uint8_t) * 3);
+
+    printf("El sizeof de header es: %d\n", (int)sizeof(header));
+
+    if (fread(header, sizeof(uint8_t) * 2, 1, pfile) == 0) {
+        perror("fread");
+        fclose(pfile);
+        return 1;
+    }
+
+    header[3] = '\0';
+
+    int w, h, s;
+
+    if (fscanf(pfile, " %d %d %d", &w, &h, &s) != 3) {
+        fprintf(stderr, "Error leyendo las caracteristicas de la imagen.\n");
+        fclose(pfile);
+        return 1;
+    }
+
+    fprintf(stdout, "Header readed: %s\n", (unsigned char *)header);
+    fprintf(stdout,
+            "Las dimensiones son %dx%d pixeles y una escala maxima de color de "
+            "%d\n",
+            w, h, s);
+
+    // consumo un caracter mas y queda listo para leer los datos de los pixeles.
+    fgetc(pfile);
+
+    unsigned char *data = NULL;
+    unsigned long pixel_count = w * h;
+
+    data = malloc(sizeof(data) * pixel_count * 3);
+
+    if (data == NULL) {
+        perror("malloc");
+        fclose(pfile);
+        return 1;
+    }
+
+    unsigned long readed =
+        fread(data, sizeof(unsigned char) * 3, pixel_count, pfile);
+
+    fprintf(stdout, "%zu pixeles leidos de %zu\n", readed, pixel_count);
+
+    if (readed != pixel_count) {
+        fprintf(stderr, "Error leyendo datos del archivo\n");
+        free(data);
+        fclose(pfile);
+    }
+
+    free(data);
+    fclose(pfile);
+    return 0;
+}