help in explaining the program
Hi,
Iam new to programming. Can anyone explain the following program?
Code:
#include "stdafx.h"
FILE *fp_dump;
/*----- Layer -----*/
/* layer Record*/
typedef struct {
USHORT usCode; /*LayerCode*/
USHORT usSubCode; /*SubCode*/
USHORT usBrandCode; /*BrandCode*/
USHORT usStartY; /*Latitude*/
USHORT usStartX; /*Longitude*/
UINT uiAR_DA; /*Offset*/
USHORT usCellSize; /*Cell Size*/
USHORT usDS; /*Relative offset*/
USHORT usKey; /*SortKey*/
} stRec_t;
/*Layer*/
typedef struct {
USHORT usRecCnt; /*Number of DataRecord*/
stRec_t *pstRec; /*Layer Record*/
} stLayer_t;
static int iGetLayerFile( char*, stLayer_t* );
static int iCodeSort(const void *, const void * );
static int iWriteLayerFile( char *, stLayer_t * );
/******* Sample main function ********/
int main( int argc, char **argv ) {
int i,j,k,l,m,sMax,dMax;
int cnt;
SearchFiles_T stSearch;
SearchFiles _T stSearchFiles;
stLayer_t stILF;
DIR* dir;
char acFileName[128],cmd[128];
char *temp, *pch;
char acILFDir[128];
char acNewILFDir[128];
char dirPath[128];
if (argv[1] == NULL || argv[2] == NULL)
{
printf("\n<Usage>\nLayerFileSort source dest\n\n");
exit( NG );
}
sMax = strlen(argv[1]);
dMax = strlen(argv[2]);
memcpy(acILFDir, argv[1],sMax+2);
memmove(acILFDir+sMax,"/\0",2);
memcpy(acNewILFDir, argv[2],dMax+2);
memmove(acNewILFDir+dMax,"/\0",2);
if ((fp_dump=fopen("LayerFile.txt", "w")) == NULL) {
printf( "LogFile Open error\n" );
exit( NG );
}
memset(&stFinds, 0, sizeof(SearchFiles_T));
/*Search ILF directories*/
if ((FindFiles(acILFDir, &stFinds)) == NG) {
exit( NG );
}
for (i=0 ; i<stFinds.iFileCnt ; i++) {
memset(&stFindsFiles, 0, sizeof(SearchFiles _T));
/*Search ILF files*/
if ((FindFiles(stFinds.pcPathName[i], &stFindsFiles)) == NG) {
exit( NG );
}
for (j=0 ; j<stFindsFiles.iFileCnt ; j++) {
printf("%5d: %s\n", i, stFindsFiles.pcPathName[j] );
/*get ILF*/
if( iGetLayerFile( stFindsFiles.pcPathName[j], &stILF ) != OK ){
printf("ILF reading error : %s\n",stFindsFiles.pcPathName[j] );
exit( NG );
}
/*sort ILF*/
qsort(stILF.pstRec,stILF.usRecCnt,sizeof(stRec_t),iCodeSort);
/*get filename*/
memcpy( acFileName, acNewILFDir,strlen(acNewILFDir));
for ( m = (int)strlen ( acNewILFDir ),l = (int)strlen ( acILFDir );
l < (int)strlen( stFindsFiles.pcPathName[j] ); l++, m++ )
acFileName[m] = stFindsFiles.pcPathName[j][l];
acFileName[m] = '\0';
temp = (char *)malloc(strlen(acFileName)+1);
if ( NULL == temp )
{
printf ("temp malloc error!");
exit (NG);
}
memcpy(temp,acFileName,strlen(acFileName)+1);
pch = (char *)malloc(strlen(acFileName)+1);
if ( NULL == pch )
{
printf("pch malloc error!");
exit (NG);
}
memcpy(pch,acFileName,strlen(acFileName)+1);
pch = strrchr(temp,'/');
cnt = pch - temp + 1;
memcpy(dirPath,temp,cnt);
dirPath[cnt] = '\0';
dir = opendir(dirPath);
if (!dir)
{
sprintf(cmd,"mkdir -m 755 -p %s",dirPath);
printf("Making directory :%s\n",dirPath);
/* printf("cmd:%s\n",cmd); */
system (cmd);
}
else closedir(dir);
/*write ILF(finshed sortting)*/
if( iWriteLayerFile ( acFileName, &stILF ) != OK ){
printf("ILF writing error : %s\n",acFileName );
exit( NG );
}
/* dump list */
for ( k = 0; k < stILF.usRecCnt; k++ ){
fprintf(fp_dump, "%s,%d,%d,%d,0x%04x,0x%04x,0x%04x,0x%02x,0x%02x,%d\n",
stFindsFiles.pcPathName[j],
stILF.pstRec[k].usCode,
stILF.pstRec[k].usSubCode,
stILF.pstRec[k].usBrandCode,
stILF.pstRec[k].usStartX,
stILF.pstRec[k].usStartY,
stILF.pstRec[k].uiAR_DA,
stILF.pstRec[k].usCellSize,
stILF.pstRec[k].usDS,
stILF.pstRec[k].usKey);
}
if(stILF.usRecCnt != 0) free (stILF.pstRec);
}
FindFree(&stFindsFiles);
}
FindFree(&stFinds);
fclose(fp_dump);
free(temp);
free(pch);
printf("Done!\n");
exit( OK );
}
/*=====================
FUNCTION : Get LayerFile
INPUT : char* -FileName
stLayer_t -Layer
RETURN : OK / NG
=======================*/
static int iGetLayerFile( char *acFileName, stLayer_t *pstILF)
{
FILE *fp;
int i,j;
USHORT usSortKey[SORT_REC] = {9126,7328,7373,7315,7387,7314,7313,7369,9999,7395,7311,7321};
pstILF->usRecCnt = 0;
if ((fp=fopen(acFileName, "rb")) == NULL) {
return ( NG );
}
fread(&pstILF->usRecCnt, 2, 1, fp);
if( pstILF->usRecCnt != 0 ){
pstILF->pstRec =
(stRec_t*)calloc(pstILF->usRecCnt,sizeof(stRec_t) );
}
for( i = 0; i < (int)pstILF->usRecCnt; i++ ){
fread(&pstILF->pstRec[i].usCode, 2, 1, fp); /* Layer Code*/
fread(&pstILF->pstRec[i].usSubCode, 2, 1, fp); /* Sub Code*/
fread(&pstILF->pstRec[i].usBrandCode, 2, 1, fp); /* Brand Code*/
fread(&pstILF->pstRec[i].usStartY, 2, 1, fp); /* Lat*/
fread(&pstILF->pstRec[i].usStartX, 2, 1, fp); /* Long*/
fread(&pstILF->pstRec[i].uiAR_DA, 4, 1, fp); /* Offset*/
fread(&pstILF->pstRec[i].usCellSize, 2, 1, fp); /* CellSize*/
fread(&pstILF->pstRec[i].usDS, 2, 1, fp); /* RelativeOffset*/
pstILF->pstRec[i].usKey = 0; /* Sort Key */
for ( j = 0; j < SORT_REC; j++ ){
if( pstILF->pstRec[i].usCode == usSortKey[j] ){
pstILF->pstRec[i].usKey = j + 1; /* Sort Key*/
break;
}
}
}
fclose( fp );
return( OK );
}
/*=====================
FUNCTION : Write LayerFile
INPUT : char* -FileName
stLayer_t -Layer
RETURN : OK / NG
=======================*/
static int iWriteLayerFile( char *acFileName, stLayer_t *pstILF)
{
FILE *fp;
int i;
if ((fp=fopen(acFileName, "wb")) == NULL) {
return ( NG );
}
fwrite(&pstILF->usRecCnt, 2, 1, fp);
for( i = 0; i < (int)pstILF->usRecCnt; i++ ){
fwrite(&pstILF->pstRec[i].usCode, 2, 1, fp); /* Layer Code*/
fwrite(&pstILF->pstRec[i].usSubCode, 2, 1, fp); /* Sub Code*/
fwrite(&pstILF->pstRec[i].usBrandCode, 2, 1, fp); /* Brand Code*/
fwrite(&pstILF->pstRec[i].usStartY, 2, 1, fp); /* Lat*/
fwrite(&pstILF->pstRec[i].usStartX, 2, 1, fp); /* Long*/
fwrite(&pstILF->pstRec[i].uiAR_DA, 4, 1, fp); /* Offset*/
fwrite(&pstILF->pstRec[i].usCellSize, 2, 1, fp); /* CellSize*/
fwrite(&pstILF->pstRec[i].usDS, 2, 1, fp); /* RelativeOffset*/
};
fclose( fp );
return( OK );
}
/*===================
FUNCTION : iCodeSort
INPUT : stLayer_t -Layer
stLayer_t -Layer
RETURN : OK / NG
====================*/
static int iCodeSort(const void *data1, const void *data2 )
{
stRec_t *pst1;
stRec_t *pst2;
int iDiff;
pst1 = (stRec_t*)data1;
pst2 = (stRec_t*)data2;
iDiff = (int)pst1->usKey - (int)pst2->usKey;
return( iDiff );
}
