snippet     sc
abbr        scanf
  scanf("%${1}", &${2});${0}

snippet     calloc
abbr        calloc
  ${1:int}* ${2:p};
  if ( NULL == ($2 = calloc(${3:10}, sizeof($1))) ) {
    printf("malloc failed\n");
    return(-1);
  }
  ${0:#:Do something with your memory};
  free($2);