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addresses #17 and allows processing of DBF files with odd header sizes #18

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addresses #17 and allows processing of DBF files with odd header sizes #18

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67 changes: 24 additions & 43 deletions src/pgdbf.c
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Original file line number Diff line number Diff line change
Expand Up @@ -46,10 +46,6 @@ int main(int argc, char **argv) {
unsigned int dbfbatchsize; /* How many DBF records to read at once */
unsigned int batchindex; /* The offset inside the current batch of
* DBF records */
int skipbytes; /* The length of the Visual FoxPro DBC in
* this file (if there is one) */
int fieldarraysize; /* The length of the field descriptor
* array */
int fieldnum; /* The current field beind processed */
uint8_t terminator; /* Testing for terminator bytes */

Expand Down Expand Up @@ -329,37 +325,30 @@ int main(int argc, char **argv) {
exitwitherror("Unable to read the entire DBF header", 1);
}

if(dbfheader.signature == 0x30) {
/* Certain DBF files have an (empty?) 263-byte buffer after the header
* information. Take that into account when calculating field counts
* and possibly seeking over it later. */
skipbytes = 263;
} else {
skipbytes = 0;
}

/* Calculate the number of fields in this file */
/* Get the size of a field entry */
dbffieldsize = sizeof(DBFFIELD);
fieldarraysize = littleint16_t(dbfheader.headerlength) - sizeof(dbfheader) - skipbytes - 1;
if(fieldarraysize % dbffieldsize == 1) {
/* Some dBASE III files include an extra terminator byte after the
* field descriptor array. If our calculations are one byte off,
* that's the cause and we have to skip the extra byte when seeking
* to the start of the records. */
skipbytes += 1;
fieldarraysize -= 1;
} else if(fieldarraysize % dbffieldsize) {
exitwitherror("The field array size is not an even multiple of the database field size", 0);
}
fieldcount = fieldarraysize / dbffieldsize;

/* Fetch the description of each field */
fields = malloc(fieldarraysize);
if(fields == NULL) {
exitwitherror("Unable to malloc the field descriptions", 1);
}
if(fread(fields, dbffieldsize, fieldcount, dbffile) != fieldcount) {
exitwitherror("Unable to read all of the field descriptions", 1);

/* Read the field entries */
fields = (DBFFIELD*)0;
for(fieldcount = 0; ; fieldcount++) {

/* Allocate space for the next field entry and read it */
fields = (DBFFIELD*)realloc((void*)fields, sizeof(DBFFIELD)*(fieldcount + 1));
if(!fields) {
exitwitherror("Unable to malloc feild list", 0);
}
if(fread(&fields[fieldcount], sizeof(DBFFIELD), 1, dbffile) != 1) {
exitwitherror("Unable to read field header", 0);
}

/* Check for the terminator */
if(fields[fieldcount].name[0] == 13)
break;
}

/* We overshot the last field entry, so we have to rewind a bit */
if(fseek(dbffile, -1*sizeof(DBFFIELD), SEEK_CUR)) {
exitwitherror("Unable to seek in the DBF file", 1);
}

/* Keep track of PostgreSQL output parameters */
Expand All @@ -371,16 +360,8 @@ int main(int argc, char **argv) {
pgfields[i].formatstring = NULL;
}

/* Check for the terminator character */
if(fread(&terminator, 1, 1, dbffile) != 1) {
exitwitherror("Unable to read the terminator byte", 1);
}
if(terminator != 13) {
exitwitherror("Invalid terminator byte", 0);
}

/* Skip the database container if necessary */
if(fseek(dbffile, skipbytes, SEEK_CUR)) {
if(fseek(dbffile, littleint16_t(dbfheader.headerlength) - ftell(dbffile), SEEK_CUR)) {
exitwitherror("Unable to seek in the DBF file", 1);
}

Expand Down