+/****************************************************************************
+ * RRDtool 1.0.28 Copyright Tobias Oetiker, 1997 - 2000
+ ****************************************************************************
+ * rrd_rpncalc.c RPN calculator functions
+ ****************************************************************************/
+
+#include "rrd_tool.h"
+#include "rrd_rpncalc.h"
+#include <limits.h>
+
+short addop2str(enum op_en op, enum op_en op_type, char *op_str,
+ char **result_str, unsigned short *offset);
+int tzoffset(time_t); /* used to implement LTIME */
+
+short rpn_compact(rpnp_t *rpnp, rpn_cdefds_t **rpnc, short *count)
+{
+ short i;
+ *count = 0;
+ /* count the number of rpn nodes */
+ while(rpnp[*count].op != OP_END) (*count)++;
+ if (++(*count) > DS_CDEF_MAX_RPN_NODES) {
+ rrd_set_error("Maximum %d RPN nodes permitted",
+ DS_CDEF_MAX_RPN_NODES);
+ return -1;
+ }
+
+ /* allocate memory */
+ *rpnc = (rpn_cdefds_t *) calloc(*count,sizeof(rpn_cdefds_t));
+ for (i = 0; rpnp[i].op != OP_END; i++)
+ {
+ (*rpnc)[i].op = (char) rpnp[i].op;
+ if (rpnp[i].op == OP_NUMBER) {
+ /* rpnp.val is a double, rpnc.val is a short */
+ double temp = floor(rpnp[i].val);
+ if (temp < SHRT_MIN || temp > SHRT_MAX) {
+ rrd_set_error(
+ "constants must be integers in the interval (%d, %d)",
+ SHRT_MIN, SHRT_MAX);
+ free(*rpnc);
+ return -1;
+ }
+ (*rpnc)[i].val = (short) temp;
+ } else if (rpnp[i].op == OP_VARIABLE) {
+ (*rpnc)[i].val = (short) rpnp[i].ptr;
+ }
+ }
+ /* terminate the sequence */
+ (*rpnc)[(*count) - 1].op = OP_END;
+ return 0;
+}
+
+rpnp_t * rpn_expand(rpn_cdefds_t *rpnc)
+{
+ short i;
+ rpnp_t *rpnp;
+
+ /* DS_CDEF_MAX_RPN_NODES is small, so at the expense of some wasted
+ * memory we avoid any reallocs */
+ rpnp = (rpnp_t *) calloc(DS_CDEF_MAX_RPN_NODES,sizeof(rpnp_t));
+ if (rpnp == NULL) return NULL;
+ for (i = 0; rpnc[i].op != OP_END; ++i)
+ {
+ rpnp[i].op = (long) rpnc[i].op;
+ if (rpnp[i].op == OP_NUMBER) {
+ rpnp[i].val = (double) rpnc[i].val;
+ } else if (rpnp[i].op == OP_VARIABLE) {
+ rpnp[i].ptr = (long) rpnc[i].val;
+ }
+ }
+ /* terminate the sequence */
+ rpnp[i].op = OP_END;
+ return rpnp;
+}
+
+/* rpn_compact2str: convert a compact sequence of RPN operator nodes back
+ * into a CDEF string. This function is used by rrd_dump.
+ * arguments:
+ * rpnc: an array of compact RPN operator nodes
+ * rrd: a pointer an rrd header (only the ds_cnt and ds_def elements need
+ * to be valid) for lookup of data source names by index
+ * str: out string, memory is allocated by the function, must be freed by the
+ * the caller */
+void rpn_compact2str(rpn_cdefds_t *rpnc,ds_def_t *ds_def,char **str)
+{
+ unsigned short i,offset = 0;
+ char buffer[7]; /* short as a string */
+
+ for (i = 0; rpnc[i].op != OP_END; i++)
+ {
+ if (i > 0) (*str)[offset++] = ',';
+
+#define add_op(VV,VVV) \
+ if (addop2str(rpnc[i].op, VV, VVV, str, &offset) == 1) continue;
+
+ if (rpnc[i].op == OP_NUMBER) {
+ /* convert a short into a string */
+#ifdef WIN32
+ _itoa(rpnc[i].val,buffer,10);
+#else
+ sprintf(buffer,"%d",rpnc[i].val);
+#endif
+ add_op(OP_NUMBER,buffer)
+ }
+
+ if (rpnc[i].op == OP_VARIABLE) {
+ char *ds_name = ds_def[rpnc[i].val].ds_nam;
+ add_op(OP_VARIABLE, ds_name)
+ }
+#undef add_op
+
+#define add_op(VV,VVV) \
+ if (addop2str(rpnc[i].op, VV, #VVV, str, &offset) == 1) continue;
+
+ add_op(OP_ADD,+)
+ add_op(OP_SUB,-)
+ add_op(OP_MUL,*)
+ add_op(OP_DIV,/)
+ add_op(OP_MOD,%)
+ add_op(OP_SIN,SIN)
+ add_op(OP_COS,COS)
+ add_op(OP_LOG,LOG)
+ add_op(OP_FLOOR,FLOOR)
+ add_op(OP_CEIL,CEIL)
+ add_op(OP_EXP,EXP)
+ add_op(OP_DUP,DUP)
+ add_op(OP_EXC,EXC)
+ add_op(OP_POP,POP)
+ add_op(OP_LT,LT)
+ add_op(OP_LE,LE)
+ add_op(OP_GT,GT)
+ add_op(OP_GE,GE)
+ add_op(OP_EQ,EQ)
+ add_op(OP_IF,IF)
+ add_op(OP_MIN,MIN)
+ add_op(OP_MAX,MAX)
+ add_op(OP_LIMIT,LIMIT)
+ add_op(OP_UNKN,UNKN)
+ add_op(OP_UN,UN)
+ add_op(OP_NEGINF,NEGINF)
+ add_op(OP_PREV,PREV)
+ add_op(OP_INF,INF)
+ add_op(OP_NOW,NOW)
+ add_op(OP_LTIME,LTIME)
+ add_op(OP_TIME,TIME)
+
+#undef add_op
+ }
+ (*str)[offset] = '\0';
+
+}
+
+short addop2str(enum op_en op, enum op_en op_type, char *op_str,
+ char **result_str, unsigned short *offset)
+{
+ if (op == op_type) {
+ short op_len;
+ op_len = strlen(op_str);
+ *result_str = (char *) rrd_realloc(*result_str,
+ (op_len + 1 + *offset)*sizeof(char));
+ if (*result_str == NULL) {
+ rrd_set_error("failed to alloc memory in addop2str");
+ return -1;
+ }
+ strncpy(&((*result_str)[*offset]),op_str,op_len);
+ *offset += op_len;
+ return 1;
+ }
+ return 0;
+}
+
+void parseCDEF_DS(char *def,rrd_t *rrd, int ds_idx)
+{
+ rpnp_t *rpnp = NULL;
+ rpn_cdefds_t *rpnc = NULL;
+ short count, i;
+
+ rpnp = rpn_parse((void*) rrd, def, &lookup_DS);
+ if (rpnp == NULL) {
+ rrd_set_error("failed to parse computed data source %s", def);
+ return;
+ }
+ /* Check for OP nodes not permitted in COMPUTE DS.
+ * Moved this check from within rpn_compact() because it really is
+ * COMPUTE DS specific. This is less efficient, but creation doesn't
+ * occur too often. */
+ for (i = 0; rpnp[i].op != OP_END; i++) {
+ if (rpnp[i].op == OP_TIME || rpnp[i].op == OP_LTIME ||
+ rpnp[i].op == OP_PREV)
+ {
+ rrd_set_error(
+ "operators time, ltime and prev not supported with DS COMPUTE");
+ free(rpnp);
+ return;
+ }
+ }
+ if (rpn_compact(rpnp,&rpnc,&count) == -1) {
+ free(rpnp);
+ return;
+ }
+ /* copy the compact rpn representation over the ds_def par array */
+ memcpy((void*) &(rrd -> ds_def[ds_idx].par[DS_cdef]),
+ (void*) rpnc, count*sizeof(rpn_cdefds_t));
+ free(rpnp);
+ free(rpnc);
+}
+
+/* lookup a data source name in the rrd struct and return the index,
+ * should use ds_match() here except:
+ * (1) need a void * pointer to the rrd
+ * (2) error handling is left to the caller
+ */
+long lookup_DS(void *rrd_vptr,char *ds_name)
+{
+ int i;
+ rrd_t *rrd;
+
+ rrd = (rrd_t *) rrd_vptr;
+
+ for (i = 0; i < rrd -> stat_head -> ds_cnt; ++i)
+ {
+ if(strcmp(ds_name,rrd -> ds_def[i].ds_nam) == 0)
+ return i;
+ }
+ /* the caller handles a bad data source name in the rpn string */
+ return -1;
+}
+
+/* rpn_parse : parse a string and generate a rpnp array; modified
+ * str2rpn() originally included in rrd_graph.c
+ * arguments:
+ * key_hash: a transparent argument passed to lookup(); conceptually this
+ * is a hash object for lookup of a numeric key given a variable name
+ * expr: the string RPN expression, including variable names
+ * lookup(): a function that retrieves a numeric key given a variable name
+ */
+rpnp_t *
+rpn_parse(void *key_hash,char *expr,long (*lookup)(void *,char*)){
+ int pos=0;
+ long steps=-1;
+ rpnp_t *rpnp;
+ char vname[30];
+
+ rpnp=NULL;
+
+ while(*expr){
+ if ((rpnp = (rpnp_t *) rrd_realloc(rpnp, (++steps + 2)*
+ sizeof(rpnp_t)))==NULL){
+ return NULL;
+ }
+
+ else if((sscanf(expr,"%lf%n",&rpnp[steps].val,&pos) == 1) && (expr[pos] == ',')){
+ rpnp[steps].op = OP_NUMBER;
+ expr+=pos;
+ }
+
+#define match_op(VV,VVV) \
+ else if (strncmp(expr, #VVV, strlen(#VVV))==0){ \
+ rpnp[steps].op = VV; \
+ expr+=strlen(#VVV); \
+ }
+
+ match_op(OP_ADD,+)
+ match_op(OP_SUB,-)
+ match_op(OP_MUL,*)
+ match_op(OP_DIV,/)
+ match_op(OP_MOD,%)
+ match_op(OP_SIN,SIN)
+ match_op(OP_COS,COS)
+ match_op(OP_LOG,LOG)
+ match_op(OP_FLOOR,FLOOR)
+ match_op(OP_CEIL,CEIL)
+ match_op(OP_EXP,EXP)
+ match_op(OP_DUP,DUP)
+ match_op(OP_EXC,EXC)
+ match_op(OP_POP,POP)
+ match_op(OP_LT,LT)
+ match_op(OP_LE,LE)
+ match_op(OP_GT,GT)
+ match_op(OP_GE,GE)
+ match_op(OP_EQ,EQ)
+ match_op(OP_IF,IF)
+ match_op(OP_MIN,MIN)
+ match_op(OP_MAX,MAX)
+ match_op(OP_LIMIT,LIMIT)
+ /* order is important here ! .. match longest first */
+ match_op(OP_UNKN,UNKN)
+ match_op(OP_UN,UN)
+ match_op(OP_NEGINF,NEGINF)
+ match_op(OP_PREV,PREV)
+ match_op(OP_INF,INF)
+ match_op(OP_NOW,NOW)
+ match_op(OP_LTIME,LTIME)
+ match_op(OP_TIME,TIME)
+
+#undef match_op
+
+
+ else if ((sscanf(expr,"%29[_A-Za-z0-9]%n",
+ vname,&pos) == 1)
+ && ((rpnp[steps].ptr = (*lookup)(key_hash,vname)) != -1)){
+ rpnp[steps].op = OP_VARIABLE;
+ expr+=pos;
+ }
+
+ else {
+ free(rpnp);
+ return NULL;
+ }
+ if (*expr == 0)
+ break;
+ if (*expr == ',')
+ expr++;
+ else {
+ free(rpnp);
+ return NULL;
+ }
+ }
+ rpnp[steps+1].op = OP_END;
+ return rpnp;
+}
+
+void
+rpnstack_init(rpnstack_t *rpnstack)
+{
+ rpnstack -> s = NULL;
+ rpnstack -> dc_stacksize = 0;
+ rpnstack -> dc_stackblock = 100;
+}
+
+void
+rpnstack_free(rpnstack_t *rpnstack)
+{
+ if (rpnstack -> s != NULL)
+ free(rpnstack -> s);
+ rpnstack -> dc_stacksize = 0;
+}
+
+/* rpn_calc: run the RPN calculator; also performs variable substitution;
+ * moved and modified from data_calc() originally included in rrd_graph.c
+ * arguments:
+ * rpnp : an array of RPN operators (including variable references)
+ * rpnstack : the initialized stack
+ * data_idx : when data_idx is a multiple of rpnp.step, the rpnp.data pointer
+ * is advanced by rpnp.ds_cnt; used only for variable substitution
+ * output : an array of output values; OP_PREV assumes this array contains
+ * the "previous" value at index position output_idx-1; the definition of
+ * "previous" depends on the calling environment
+ * output_idx : an index into the output array in which to store the output
+ * of the RPN calculator
+ * returns: -1 if the computation failed (also calls rrd_set_error)
+ * 0 on success
+ */
+short
+rpn_calc(rpnp_t *rpnp, rpnstack_t *rpnstack, long data_idx,
+ rrd_value_t *output, int output_idx)
+{
+ int rpi;
+ long stptr = -1;
+
+ /* process each op from the rpn in turn */
+ for (rpi=0; rpnp[rpi].op != OP_END; rpi++){
+ /* allocate or grow the stack */
+ if (stptr + 5 > rpnstack -> dc_stacksize){
+ /* could move this to a separate function */
+ rpnstack -> dc_stacksize += rpnstack -> dc_stackblock;
+ rpnstack -> s = rrd_realloc(rpnstack -> s,
+ (rpnstack -> dc_stacksize)*sizeof(*(rpnstack -> s)));
+ if (rpnstack -> s == NULL){
+ rrd_set_error("RPN stack overflow");
+ return -1;
+ }
+ }
+ switch (rpnp[rpi].op){
+ case OP_NUMBER:
+ rpnstack -> s[++stptr] = rpnp[rpi].val;
+ break;
+ case OP_VARIABLE:
+ /* make sure we pull the correct value from the *.data array
+ * adjust the pointer into the array acordingly.
+ * Advance the ptr one row in the rra (skip over
+ * non-relevant data sources) */
+ if (data_idx % rpnp[rpi].step == 0){
+ rpnp[rpi].data += rpnp[rpi].ds_cnt;
+ }
+ rpnstack -> s[++stptr] = *(rpnp[rpi].data);
+ break;
+ case OP_PREV:
+ if ((output_idx-1) <= 0) {
+ rpnstack -> s[++stptr] = DNAN;
+ } else {
+ rpnstack -> s[++stptr] = output[output_idx-1];
+ }
+ break;
+ case OP_UNKN:
+ rpnstack -> s[++stptr] = DNAN;
+ break;
+ case OP_INF:
+ rpnstack -> s[++stptr] = DINF;
+ break;
+ case OP_NEGINF:
+ rpnstack -> s[++stptr] = -DINF;
+ break;
+ case OP_NOW:
+ rpnstack -> s[++stptr] = (double)time(NULL);
+ break;
+ case OP_TIME:
+ /* HACK: this relies on the data_idx being the time,
+ * which the within-function scope is unaware of */
+ rpnstack -> s[++stptr] = (double) data_idx;
+ break;
+ case OP_LTIME:
+ rpnstack -> s[++stptr] = (double) tzoffset(data_idx) + (double)data_idx;
+ break;
+ case OP_ADD:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1]
+ + rpnstack -> s[stptr];
+ stptr--;
+ break;
+ case OP_SUB:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] - rpnstack -> s[stptr];
+ stptr--;
+ break;
+ case OP_MUL:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr-1] = (rpnstack -> s[stptr-1]) * (rpnstack -> s[stptr]);
+ stptr--;
+ break;
+ case OP_DIV:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] / rpnstack -> s[stptr];
+ stptr--;
+ break;
+ case OP_MOD:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr-1] = fmod(rpnstack -> s[stptr-1],rpnstack -> s[stptr]);
+ stptr--;
+ break;
+ case OP_SIN:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr] = sin(rpnstack -> s[stptr]);
+ break;
+ case OP_COS:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr] = cos(rpnstack -> s[stptr]);
+ break;
+ case OP_CEIL:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr] = ceil(rpnstack -> s[stptr]);
+ break;
+ case OP_FLOOR:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr] = floor(rpnstack -> s[stptr]);
+ break;
+ case OP_LOG:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr] = log(rpnstack -> s[stptr]);
+ break;
+ case OP_DUP:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr+1] = rpnstack -> s[stptr];
+ stptr++;
+ break;
+ case OP_POP:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ stptr--;
+ break;
+ case OP_EXC:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ } else {
+ double dummy;
+ dummy = rpnstack -> s[stptr] ;
+ rpnstack -> s[stptr] = rpnstack -> s[stptr-1];
+ rpnstack -> s[stptr-1] = dummy;
+ }
+ break;
+ case OP_EXP:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack -> s[stptr] = exp(rpnstack -> s[stptr]);
+ break;
+ case OP_LT:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ if (isnan(rpnstack -> s[stptr-1]))
+ ;
+ else if (isnan(rpnstack -> s[stptr]))
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+ else
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] < rpnstack -> s[stptr] ? 1.0 : 0.0;
+ stptr--;
+ break;
+ case OP_LE:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ if (isnan(rpnstack -> s[stptr-1]))
+ ;
+ else if (isnan(rpnstack -> s[stptr]))
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+ else
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] <= rpnstack -> s[stptr] ? 1.0 : 0.0;
+ stptr--;
+ break;
+ case OP_GT:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ if (isnan(rpnstack -> s[stptr-1]))
+ ;
+ else if (isnan(rpnstack -> s[stptr]))
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+ else
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] > rpnstack -> s[stptr] ? 1.0 : 0.0;
+ stptr--;
+ break;
+ case OP_GE:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ if (isnan(rpnstack -> s[stptr-1]))
+ ;
+ else if (isnan(rpnstack -> s[stptr]))
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+ else
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] >= rpnstack -> s[stptr] ? 1.0 : 0.0;
+ stptr--;
+ break;
+ case OP_EQ:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ if (isnan(rpnstack -> s[stptr-1]))
+ ;
+ else if (isnan(rpnstack -> s[stptr]))
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+ else
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] == rpnstack -> s[stptr] ? 1.0 : 0.0;
+ stptr--;
+ break;
+ case OP_IF:
+ if(stptr<2){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack->s[stptr-2] = rpnstack->s[stptr-2] != 0.0 ? rpnstack->s[stptr-1] : rpnstack->s[stptr];
+ stptr--;
+ stptr--;
+ break;
+ case OP_MIN:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ if (isnan(rpnstack->s[stptr-1]))
+ ;
+ else if (isnan(rpnstack->s[stptr]))
+ rpnstack->s[stptr-1] = rpnstack->s[stptr];
+ else if (rpnstack->s[stptr-1] > rpnstack->s[stptr])
+ rpnstack->s[stptr-1] = rpnstack->s[stptr];
+ stptr--;
+ break;
+ case OP_MAX:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ if (isnan(rpnstack->s[stptr-1]))
+ ;
+ else if (isnan(rpnstack->s[stptr]))
+ rpnstack->s[stptr-1] = rpnstack->s[stptr];
+ else if (rpnstack->s[stptr-1] < rpnstack->s[stptr])
+ rpnstack->s[stptr-1] = rpnstack->s[stptr];
+ stptr--;
+ break;
+ case OP_LIMIT:
+ if(stptr<2){
+ rrd_set_error("RPN stack underflow");
+ free(rpnstack->s);
+ return -1;
+ }
+ if (isnan(rpnstack->s[stptr-2]))
+ ;
+ else if (isnan(rpnstack->s[stptr-1]))
+ rpnstack->s[stptr-2] = rpnstack->s[stptr-1];
+ else if (isnan(rpnstack->s[stptr]))
+ rpnstack->s[stptr-2] = rpnstack->s[stptr];
+ else if (rpnstack->s[stptr-2] < rpnstack->s[stptr-1])
+ rpnstack->s[stptr-2] = DNAN;
+ else if (rpnstack->s[stptr-2] > rpnstack->s[stptr])
+ rpnstack->s[stptr-2] = DNAN;
+ stptr-=2;
+ break;
+ case OP_UN:
+ if(stptr<0){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ rpnstack->s[stptr] = isnan(rpnstack->s[stptr]) ? 1.0 : 0.0;
+ break;
+ case OP_END:
+ break;
+ }
+ }
+ if(stptr!=0){
+ rrd_set_error("RPN final stack size != 1");
+ return -1;
+ }
+
+ output[output_idx] = rpnstack->s[0];
+ return 0;
+}
+
+/* figure out what the local timezone offset for any point in
+ time was. Return it in seconds */
+int
+tzoffset( time_t now ){
+ int gm_sec, gm_min, gm_hour, gm_yday, gm_year,
+ l_sec, l_min, l_hour, l_yday, l_year;
+ struct tm *t;
+ int off;
+ t = gmtime(&now);
+ gm_sec = t->tm_sec;
+ gm_min = t->tm_min;
+ gm_hour = t->tm_hour;
+ gm_yday = t->tm_yday;
+ gm_year = t->tm_year;
+ t = localtime(&now);
+ l_sec = t->tm_sec;
+ l_min = t->tm_min;
+ l_hour = t->tm_hour;
+ l_yday = t->tm_yday;
+ l_year = t->tm_year;
+ off = (l_sec-gm_sec)+(l_min-gm_min)*60+(l_hour-gm_hour)*3600;
+ if ( l_yday > gm_yday || l_year > gm_year){
+ off += 24*3600;
+ } else if ( l_yday < gm_yday || l_year < gm_year){
+ off -= 24*3600;
+ }
+
+ return off;
+}