cc -Wall picfs.c backup_app/backup_client.c `pkg-config fuse --cflags --libs` `pkg-config libexif --cflags --libs` -o picfs
picfs.c: In function ‘parse_exif_timestamp’:
picfs.c:76:20: warning: unused variable ‘byteOrder’ [-Wunused-variable]
      ExifByteOrder byteOrder = exif_data_get_byte_order(exifData);
                    ^
picfs.c: In function ‘sort’:
picfs.c:173:3: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘char *’ [-Wformat=]
   sprintf(yearString, "/%d", result[0]);
   ^
backup_app/backup_client.c: In function ‘backup_close’:
backup_app/backup_client.c:82:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 1);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c: In function ‘list_directory’:
backup_app/backup_client.c:105:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 1);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:112:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 4);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:118:2: warning: pointer targets in passing argument 1 of ‘backup_recv’ differ in signedness [-Wpointer-sign]
  backup_recv(recvBuffer, 4);
  ^
backup_app/backup_client.c:69:5: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 int backup_recv(char* buffer, int readLength) {
     ^
backup_app/backup_client.c:129:2: warning: pointer targets in passing argument 1 of ‘backup_recv’ differ in signedness [-Wpointer-sign]
  backup_recv(recvBuffer, 4);
  ^
backup_app/backup_client.c:69:5: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 int backup_recv(char* buffer, int readLength) {
     ^
backup_app/backup_client.c:137:2: warning: pointer targets in passing argument 1 of ‘backup_recv’ differ in signedness [-Wpointer-sign]
  backup_recv(directoryContent, directoryContentLength);
  ^
backup_app/backup_client.c:69:5: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 int backup_recv(char* buffer, int readLength) {
     ^
backup_app/backup_client.c:139:2: warning: pointer targets in return differ in signedness [-Wpointer-sign]
  return directoryContent;
  ^
backup_app/backup_client.c:98:6: warning: unused variable ‘j’ [-Wunused-variable]
  int j;
      ^
backup_app/backup_client.c: In function ‘pull_file’:
backup_app/backup_client.c:158:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 1);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:165:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 4);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:171:2: warning: pointer targets in passing argument 1 of ‘backup_recv’ differ in signedness [-Wpointer-sign]
  backup_recv(recvBuffer, 4);
  ^
backup_app/backup_client.c:69:5: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 int backup_recv(char* buffer, int readLength) {
     ^
backup_app/backup_client.c:187:6: error: redeclaration of ‘i’ with no linkage
  int i = 0;
      ^
backup_app/backup_client.c:145:6: note: previous declaration of ‘i’ was here
  int i;
      ^
backup_app/backup_client.c:207:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 1);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c: In function ‘post_file’:
backup_app/backup_client.c:231:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 1);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:238:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 4);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:248:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 4);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:264:2: warning: pointer targets in passing argument 1 of ‘backup_recv’ differ in signedness [-Wpointer-sign]
  backup_recv(recvBuffer, 1);
  ^
backup_app/backup_client.c:69:5: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 int backup_recv(char* buffer, int readLength) {
     ^
backup_app/backup_client.c: In function ‘create_dir’:
backup_app/backup_client.c:276:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 1);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:283:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 4);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c: In function ‘getFilesOnServer’:
backup_app/backup_client.c:296:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 1);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:304:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 4);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:311:2: warning: pointer targets in passing argument 1 of ‘backup_recv’ differ in signedness [-Wpointer-sign]
  backup_recv(recvBuffer, 4);
  ^
backup_app/backup_client.c:69:5: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 int backup_recv(char* buffer, int readLength) {
     ^
backup_app/backup_client.c: In function ‘isEntryFile’:
backup_app/backup_client.c:329:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 1);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:341:2: warning: pointer targets in passing argument 1 of ‘backup_send’ differ in signedness [-Wpointer-sign]
  backup_send(sendBuffer, 4);
  ^
backup_app/backup_client.c:60:6: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 void backup_send(char* data, int length) {
      ^
backup_app/backup_client.c:347:2: warning: pointer targets in passing argument 1 of ‘backup_recv’ differ in signedness [-Wpointer-sign]
  backup_recv(recvBuffer, 1);
  ^
backup_app/backup_client.c:69:5: note: expected ‘char *’ but argument is of type ‘unsigned char *’
 int backup_recv(char* buffer, int readLength) {
     ^
make: *** [all] Error 1