From f3bf15e4844454338fe42d5e93b897c7a61824a6 Mon Sep 17 00:00:00 2001 From: marshmellow42 Date: Mon, 9 Feb 2015 11:11:04 -0500 Subject: [PATCH] lf/data combined detectclock functions to one cleaned up detect clock functions - now uses one main function that takes a char argument to select which modulation to detect the clock for REMOVED commands: pskdetectclock, nrzdetectclock, fskfcdetect. renamed DetectClock function to DetectAskClock to be more descriptive. --- client/cmddata.c | 107 ++++++++++----------------------- client/cmddata.h | 4 -- client/cmdlf.c | 4 +- client/cmdlfem4x.c | 2 +- client/graph.c | 143 ++++++++++++++++++++++++++++----------------- client/graph.h | 7 ++- common/lfdemod.c | 96 +++++++++++++++--------------- 7 files changed, 177 insertions(+), 186 deletions(-) diff --git a/client/cmddata.c b/client/cmddata.c index e5463175..1bd3f6de 100644 --- a/client/cmddata.c +++ b/client/cmddata.c @@ -636,7 +636,7 @@ int CmdBitstream(const char *Cmd) } /* Get our clock */ - clock = GetClock(Cmd, high, 1); + clock = GetAskClock(Cmd, high, 1); gtl = ClearGraph(0); bit = 0; @@ -781,10 +781,33 @@ int CmdAskEdgeDetect(const char *Cmd) /* Print our clock rate */ // uses data from graphbuffer +// adjusted to take char parameter for type of modulation to find the clock - by marshmellow. int CmdDetectClockRate(const char *Cmd) { - int ans = GetClock("",0,0); - return ans; + char cmdp = param_getchar(Cmd, 0); + if (strlen(Cmd) > 3 || strlen(Cmd) == 0 || cmdp == 'h' || cmdp == 'H') { + PrintAndLog("Usage: data detectclock [modulation]"); + PrintAndLog(" [modulation as char], specify the modulation type you want to detect the clock of"); + PrintAndLog(" 'a' = ask, 'f' = fsk, 'n' = nrz/direct, 'p' = psk"); + PrintAndLog(""); + PrintAndLog(" sample: data detectclock a = detect the clock of an ask modulated wave in the GraphBuffer"); + PrintAndLog(" data detectclock f = detect the clock of an fsk modulated wave in the GraphBuffer"); + PrintAndLog(" data detectclock p = detect the clock of an psk modulated wave in the GraphBuffer"); + PrintAndLog(" data detectclock n = detect the clock of an nrz/direct modulated wave in the GraphBuffer"); + } + int ans=0; + if (cmdp == 'a'){ + ans = GetAskClock("", true, false); + } else if (cmdp == 'f'){ + ans = GetFskClock("", true, false); + } else if (cmdp == 'n'){ + ans = GetNrzClock("", true, false); + } else if (cmdp == 'p'){ + ans = GetPskClock("", true, false); + } else { + PrintAndLog ("Please specify a valid modulation to detect the clock of - see option h for help"); + } + return ans; } //by marshmellow @@ -995,7 +1018,6 @@ int CmdFSKdemodParadox(const char *Cmd) return 1; } - //by marshmellow //IO-Prox demod - FSK RF/64 with preamble of 000000001 //print ioprox ID and some format details @@ -1075,7 +1097,6 @@ int CmdFSKdemodIO(const char *Cmd) return 1; } - //by marshmellow //AWID Prox demod - FSK RF/50 with preamble of 00000001 (always a 96 bit data stream) //print full AWID Prox ID and some bit format details if found @@ -1420,55 +1441,6 @@ int CmdFSKdemod(const char *Cmd) //old CmdFSKdemod needs updating return 0; } -//by marshmellow -//attempt to detect the field clock and bit clock for FSK -int CmdFSKfcDetect(const char *Cmd) -{ - uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0}; - size_t size = getFromGraphBuf(BitStream); - if (size==0) return 0; - uint8_t dummy = 0; - uint16_t ans = countFC(BitStream, size, &dummy); - if (ans==0) { - if (g_debugMode) PrintAndLog("DEBUG: No data found"); - return 0; - } - uint8_t fc1, fc2; - fc1 = (ans >> 8) & 0xFF; - fc2 = ans & 0xFF; - - uint8_t rf1 = detectFSKClk(BitStream, size, fc1, fc2); - if (rf1==0) { - if (g_debugMode) PrintAndLog("DEBUG: Clock detect error"); - return 0; - } - if ((fc1==10 && fc2==8) || (fc1==8 && fc2==5)){ - PrintAndLog("Detected Field Clocks: FC/%d, FC/%d - Bit Clock: RF/%d", fc1, fc2, rf1); - return 1; - } - if (g_debugMode){ - PrintAndLog("DEBUG: unknown fsk field clock detected"); - PrintAndLog("Detected Field Clocks: FC/%d, FC/%d - Bit Clock: RF/%d", fc1, fc2, rf1); - } - return 0; -} - -//by marshmellow -//attempt to detect the bit clock for PSK modulations -int CmdDetectPSKClockRate(const char *Cmd) -{ - GetPskClock("",0,0); - return 0; -} - -//by marshmellow -//attempt to detect the bit clock for NRZ modulations -int CmdDetectNRZClockRate(const char *Cmd) -{ - GetNrzClock("",0,0); - return 0; -} - //by marshmellow //attempt to psk1 demod graph buffer int PSKDemod(const char *Cmd, uint8_t verbose) @@ -1504,7 +1476,6 @@ int PSKDemod(const char *Cmd, uint8_t verbose) return errCnt; } - // Indala 26 bit decode // by marshmellow // optional arguments - same as CmdpskNRZrawDemod (clock & invert) @@ -1586,20 +1557,6 @@ int CmdIndalaDecode(const char *Cmd) return 1; } -/* -//by marshmellow -//attempt to clean psk wave noise after a peak -//NOTE RELIES ON PEAKS :( -int CmdPskClean(const char *Cmd) -{ - uint8_t bitStream[MAX_GRAPH_TRACE_LEN]={0}; - size_t bitLen = getFromGraphBuf(bitStream); - pskCleanWave(bitStream, bitLen); - setGraphBuf(bitStream, bitLen); - return 0; -} -*/ - // by marshmellow // takes 3 arguments - clock, invert, maxErr as integers // attempts to demodulate nrz only @@ -2046,7 +2003,7 @@ int CmdManchesterDemod(const char *Cmd) } /* Get our clock */ - clock = GetClock(Cmd, high, 1); + clock = GetAskClock(Cmd, high, 1); int tolerance = clock/4; @@ -2206,7 +2163,7 @@ int CmdManchesterMod(const char *Cmd) int bit, lastbit, wave; /* Get our clock */ - clock = GetClock(Cmd, 0, 1); + clock = GetAskClock(Cmd, 0, 1); wave = 0; lastbit = 1; @@ -2385,10 +2342,10 @@ static command_t CommandTable[] = {"bitstream", CmdBitstream, 1, "[clock rate] -- Convert waveform into a bitstream"}, {"buffclear", CmdBuffClear, 1, "Clear sample buffer and graph window"}, {"dec", CmdDec, 1, "Decimate samples"}, - {"detectclock", CmdDetectClockRate, 1, "Detect ASK clock rate"}, + {"detectclock", CmdDetectClockRate, 1, "[modulation] Detect clock rate (options: 'a','f','n','p' for ask, fsk, nrz, psk respectively)"}, {"fskdemod", CmdFSKdemod, 1, "Demodulate graph window as a HID FSK"}, {"fskawiddemod", CmdFSKdemodAWID, 1, "Demodulate graph window as an AWID FSK tag using raw"}, - {"fskfcdetect", CmdFSKfcDetect, 1, "Try to detect the Field Clock of an FSK wave"}, + //{"fskfcdetect", CmdFSKfcDetect, 1, "Try to detect the Field Clock of an FSK wave"}, {"fskhiddemod", CmdFSKdemodHID, 1, "Demodulate graph window as a HID FSK tag using raw"}, {"fskiodemod", CmdFSKdemodIO, 1, "Demodulate graph window as an IO Prox tag FSK using raw"}, {"fskpyramiddemod",CmdFSKdemodPyramid,1, "Demodulate graph window as a Pyramid FSK tag using raw"}, @@ -2405,10 +2362,10 @@ static command_t CommandTable[] = {"manrawdecode", Cmdmandecoderaw, 1, "Manchester decode binary stream already in graph buffer"}, {"manmod", CmdManchesterMod, 1, "[clock rate] -- Manchester modulate a binary stream"}, {"norm", CmdNorm, 1, "Normalize max/min to +/-128"}, - {"nrzdetectclock",CmdDetectNRZClockRate, 1, "Detect ASK, PSK, or NRZ clock rate"}, + //{"nrzdetectclock",CmdDetectNRZClockRate, 1, "Detect ASK, PSK, or NRZ clock rate"}, {"nrzrawdemod", CmdNRZrawDemod, 1, "[clock] [invert<0|1>] [maxErr] -- Attempt to demodulate nrz tags and output binary (args optional)"}, {"plot", CmdPlot, 1, "Show graph window (hit 'h' in window for keystroke help)"}, - {"pskdetectclock",CmdDetectPSKClockRate, 1, "Detect ASK, PSK, or NRZ clock rate"}, + //{"pskdetectclock",CmdDetectPSKClockRate, 1, "Detect ASK, PSK, or NRZ clock rate"}, {"pskindalademod",CmdIndalaDecode, 1, "[clock] [invert<0|1>] -- Attempt to demodulate psk1 indala tags and output ID binary & hex (args optional)"}, {"psk1rawdemod", CmdPSK1rawDemod, 1, "[clock] [invert<0|1>] [maxErr] -- Attempt to demodulate psk1 tags and output binary (args optional)"}, {"psk2rawdemod", CmdPSK2rawDemod, 1, "[clock] [invert<0|1>] [maxErr] -- Attempt to demodulate psk2 tags and output binary (args optional)"}, diff --git a/client/cmddata.h b/client/cmddata.h index 42954cbe..29b3bbc9 100644 --- a/client/cmddata.h +++ b/client/cmddata.h @@ -27,17 +27,13 @@ int CmdBitstream(const char *Cmd); int CmdBuffClear(const char *Cmd); int CmdDec(const char *Cmd); int CmdDetectClockRate(const char *Cmd); -int CmdDetectNRZClockRate(const char *Cmd); -int CmdDetectPSKClockRate(const char *Cmd); int CmdFSKdemodAWID(const char *Cmd); int CmdFSKdemod(const char *Cmd); int CmdFSKdemodHID(const char *Cmd); int CmdFSKdemodIO(const char *Cmd); int CmdFSKdemodParadox(const char *Cmd); int CmdFSKdemodPyramid(const char *Cmd); -int CmdFSKfcDetect(const char *Cmd); int CmdFSKrawdemod(const char *Cmd); -int CmdDetectPskClockRate(const char *Cmd); int CmdPSK1rawDemod(const char *Cmd); int CmdPSK2rawDemod(const char *Cmd); int CmdGrid(const char *Cmd); diff --git a/client/cmdlf.c b/client/cmdlf.c index 27e764a2..b7c1b13f 100644 --- a/client/cmdlf.c +++ b/client/cmdlf.c @@ -728,8 +728,8 @@ int CmdLFfind(const char *Cmd) if (testRaw=='u' || testRaw=='U'){ //test unknown tag formats (raw mode) PrintAndLog("\nChecking for Unknown tags:\n"); - ans=CmdFSKfcDetect(""); - if (ans == 1){ //fsk + ans=CmdDetectClockRate("f"); + if (ans != 0){ //fsk ans=CmdFSKrawdemod(""); if (ans>0) { PrintAndLog("\nUnknown FSK Modulated Tag Found!"); diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c index 95b0342d..232d5635 100644 --- a/client/cmdlfem4x.c +++ b/client/cmdlfem4x.c @@ -61,7 +61,7 @@ int CmdEM410xRead(const char *Cmd) } /* get clock */ - clock = GetClock(Cmd, high, 0); + clock = GetAskClock(Cmd, false, false); /* parity for our 4 columns */ parity[0] = parity[1] = parity[2] = parity[3] = 0; diff --git a/client/graph.c b/client/graph.c index f508fe88..11dbc4d5 100644 --- a/client/graph.c +++ b/client/graph.c @@ -76,33 +76,6 @@ size_t getFromGraphBuf(uint8_t *buff) return i; } - -// Get or auto-detect clock rate -int GetClock(const char *str, int peak, int verbose) -{ - int clock; - sscanf(str, "%i", &clock); - if (!strcmp(str, "")) - clock = 0; - - // Auto-detect clock - if (!clock) - { - uint8_t grph[MAX_GRAPH_TRACE_LEN]={0}; - size_t size = getFromGraphBuf(grph); - if ( size == 0 ) { - PrintAndLog("Failed to copy from graphbuffer"); - return -1; - } - DetectASKClock(grph,size,&clock,20); - // Only print this message if we're not looping something - if (!verbose){ - PrintAndLog("Auto-detected clock rate: %d", clock); - } - } - return clock; -} - // A simple test to see if there is any data inside Graphbuffer. bool HasGraphData(){ @@ -135,52 +108,116 @@ void DetectHighLowInGraph(int *high, int *low, bool addFuzz) { } } -int GetPskClock(const char *str, int peak, int verbose) +// Get or auto-detect ask clock rate +int GetAskClock(const char str[], bool printAns, bool verbose) { int clock; sscanf(str, "%i", &clock); if (!strcmp(str, "")) clock = 0; + if (clock != 0) + return clock; // Auto-detect clock - if (!clock) - { - uint8_t grph[MAX_GRAPH_TRACE_LEN]={0}; - size_t size = getFromGraphBuf(grph); - if ( size == 0 ) { + uint8_t grph[MAX_GRAPH_TRACE_LEN]={0}; + size_t size = getFromGraphBuf(grph); + if (size == 0) { + if (verbose) PrintAndLog("Failed to copy from graphbuffer"); - return -1; - } - clock = DetectPSKClock(grph,size,0); - // Only print this message if we're not looping something - if (!verbose){ - PrintAndLog("Auto-detected clock rate: %d", clock); - } + return -1; + } + DetectASKClock(grph, size, &clock, 20); + // Only print this message if we're not looping something + if (printAns){ + PrintAndLog("Auto-detected clock rate: %d", clock); } return clock; } -int GetNrzClock(const char *str, int peak, int verbose) +int GetPskClock(const char str[], bool printAns, bool verbose) +{ + int clock; + sscanf(str, "%i", &clock); + if (!strcmp(str, "")) + clock = 0; + + if (clock!=0) + return clock; + // Auto-detect clock + uint8_t grph[MAX_GRAPH_TRACE_LEN]={0}; + size_t size = getFromGraphBuf(grph); + if ( size == 0 ) { + if (verbose) + PrintAndLog("Failed to copy from graphbuffer"); + return -1; + } + clock = DetectPSKClock(grph,size,0); + // Only print this message if we're not looping something + if (printAns){ + PrintAndLog("Auto-detected clock rate: %d", clock); + } + return clock; +} + +uint8_t GetNrzClock(const char str[], bool printAns, bool verbose) { int clock; sscanf(str, "%i", &clock); if (!strcmp(str, "")) clock = 0; + if (clock!=0) + return clock; // Auto-detect clock - if (!clock) - { - uint8_t grph[MAX_GRAPH_TRACE_LEN]={0}; - size_t size = getFromGraphBuf(grph); - if ( size == 0 ) { + uint8_t grph[MAX_GRAPH_TRACE_LEN]={0}; + size_t size = getFromGraphBuf(grph); + if ( size == 0 ) { + if (verbose) PrintAndLog("Failed to copy from graphbuffer"); - return -1; - } - clock = DetectNRZClock(grph,size,0); - // Only print this message if we're not looping something - if (!verbose){ - PrintAndLog("Auto-detected clock rate: %d", clock); - } + return -1; + } + clock = DetectNRZClock(grph, size, 0); + // Only print this message if we're not looping something + if (printAns){ + PrintAndLog("Auto-detected clock rate: %d", clock); } return clock; } +//by marshmellow +//attempt to detect the field clock and bit clock for FSK +uint8_t GetFskClock(const char str[], bool printAns, bool verbose) +{ + int clock; + sscanf(str, "%i", &clock); + if (!strcmp(str, "")) + clock = 0; + if (clock != 0) return (uint8_t)clock; + + uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0}; + size_t size = getFromGraphBuf(BitStream); + if (size==0) return 0; + uint8_t dummy = 0; + uint16_t ans = countFC(BitStream, size, &dummy); + if (ans==0) { + if (verbose) PrintAndLog("DEBUG: No data found"); + return 0; + } + uint8_t fc1, fc2; + fc1 = (ans >> 8) & 0xFF; + fc2 = ans & 0xFF; + + uint8_t rf1 = detectFSKClk(BitStream, size, fc1, fc2); + if (rf1==0) { + if (verbose) PrintAndLog("DEBUG: Clock detect error"); + return 0; + } + if ((fc1==10 && fc2==8) || (fc1==8 && fc2==5)){ + if (printAns) PrintAndLog("Detected Field Clocks: FC/%d, FC/%d - Bit Clock: RF/%d", fc1, fc2, rf1); + return rf1; + } + if (verbose){ + PrintAndLog("DEBUG: unknown fsk field clock detected"); + PrintAndLog("Detected Field Clocks: FC/%d, FC/%d - Bit Clock: RF/%d", fc1, fc2, rf1); + } + return 0; +} diff --git a/client/graph.h b/client/graph.h index 279b5f7b..e4872afc 100644 --- a/client/graph.h +++ b/client/graph.h @@ -16,9 +16,10 @@ void AppendGraph(int redraw, int clock, int bit); int ClearGraph(int redraw); //int DetectClock(int peak); size_t getFromGraphBuf(uint8_t *buff); -int GetClock(const char *str, int peak, int verbose); -int GetPskClock(const char *str, int peak, int verbose); -int GetNrzClock(const char *str, int peak, int verbose); +int GetAskClock(const char str[], bool printAns, bool verbose); +int GetPskClock(const char str[], bool printAns, bool verbose); +uint8_t GetNrzClock(const char str[], bool printAns, bool verbose); +uint8_t GetFskClock(const char str[], bool printAns, bool verbose); void setGraphBuf(uint8_t *buff, size_t size); bool HasGraphData(); diff --git a/common/lfdemod.c b/common/lfdemod.c index 448195f2..47e63ef6 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -50,7 +50,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) for (uint8_t i = 0; i < bitLen; i++){ ans ^= ((bits >> i) & 1); } - //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType); + //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType); return (ans == pType); } @@ -244,14 +244,14 @@ int ManchesterEncode(uint8_t *BitStream, size_t size) { size_t modIdx=20000, i=0; if (size>modIdx) return -1; - for (size_t idx=0; idx < size; idx++){ - BitStream[idx+modIdx++] = BitStream[idx]; - BitStream[idx+modIdx++] = BitStream[idx]^1; - } - for (; i<(size*2); i++){ - BitStream[i] = BitStream[i+20000]; - } - return i; + for (size_t idx=0; idx < size; idx++){ + BitStream[idx+modIdx++] = BitStream[idx]; + BitStream[idx+modIdx++] = BitStream[idx]^1; + } + for (; i<(size*2); i++){ + BitStream[i] = BitStream[i+20000]; + } + return i; } //by marshmellow @@ -331,23 +331,23 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) //by marshmellow void askAmp(uint8_t *BitStream, size_t size) { - int shift = 127; - int shiftedVal=0; - for(int i = 1; i=30) //large jump up - shift=127; - else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down - shift=-127; - - shiftedVal=BitStream[i]+shift; - - if (shiftedVal>255) - shiftedVal=255; - else if (shiftedVal<0) - shiftedVal=0; - BitStream[i-1] = shiftedVal; - } - return; + int shift = 127; + int shiftedVal=0; + for(int i = 1; i=30) //large jump up + shift=127; + else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down + shift=-127; + + shiftedVal=BitStream[i]+shift; + + if (shiftedVal>255) + shiftedVal=255; + else if (shiftedVal<0) + shiftedVal=0; + BitStream[i-1] = shiftedVal; + } + return; } //by marshmellow @@ -712,7 +712,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p for (int word = 0; word < (bLen); word+=pLen){ for (int bit=0; bit < pLen; bit++){ parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; - BitStream[j++] = (BitStream[startIdx+word+bit]); + BitStream[j++] = (BitStream[startIdx+word+bit]); } j--; // if parity fails then return 0 @@ -750,17 +750,17 @@ int AWIDdemodFSK(uint8_t *dest, size_t *size) // FSK Demod then try to locate an Farpointe Data (pyramid) ID int PyramiddemodFSK(uint8_t *dest, size_t *size) { - //make sure buffer has data - if (*size < 128*50) return -5; + //make sure buffer has data + if (*size < 128*50) return -5; - //test samples are not just noise - if (justNoise(dest, *size)) return -1; + //test samples are not just noise + if (justNoise(dest, *size)) return -1; - // FSK demodulator - *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 - if (*size < 128) return -2; //did we get a good demod? + // FSK demodulator + *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 + if (*size < 128) return -2; //did we get a good demod? - uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; + uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; size_t startIdx = 0; uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); if (errChk == 0) return -4; //preamble not found @@ -794,7 +794,7 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) int i=0; int clk[]={8,16,32,40,50,64,100,128,256}; int loopCnt = 256; //don't need to loop through entire array... - if (size == 0) return -1; + if (size == 0) return -1; if (size0 && maxPeak < peakcnt){ - maxPeak = peakcnt; + maxPeak = peakcnt; } peakcnt=0; } @@ -1041,7 +1041,7 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock) int iii=7; int best=0; for (iii=7; iii > 0; iii--){ - if (peaksdet[iii] > peaksdet[best]){ + if (peaksdet[iii] > peaksdet[best]){ best = iii; } //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]); @@ -1306,7 +1306,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc uint16_t rfCounter = 0; uint8_t firstBitFnd = 0; size_t i; - if (size == 0) return 0; + if (size == 0) return 0; uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2); rfLensFnd=0; @@ -1329,7 +1329,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc fcCounter = fcLow; else //set it to the large fc fcCounter = fcHigh; - + //look for bit clock (rf/xx) if ((fcCounterlastFCcnt)){ //not the same size as the last wave - start of new bit sequence @@ -1496,7 +1496,7 @@ uint8_t countPSK_FC(uint8_t *BitStream, size_t size) uint8_t fcLensFnd = 0; uint32_t fcCounter = 0; size_t i; - if (size == 0) return 0; + if (size == 0) return 0; // prime i to first up transition for (i = 1; i < size-1; i++) @@ -1548,7 +1548,7 @@ uint8_t countPSK_FC(uint8_t *BitStream, size_t size) int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) { uint16_t loopCnt = 4096; //don't need to loop through entire array... - if (size == 0) return -1; + if (size == 0) return -1; if (*size