int main(int argc, char *argv[]){
char *prog;
int i;
if(argc>1){
newargv=malloc(argc * sizeof(char*));
for(i=1;i<argc;i++){
newargv[i-1]=argv[i];
}
newargv[i]=NULL;
forkMe(argv[1]);
}
return 0;
}
int main(int argc, char* argv[]){
int rv;
int inputFD;
int outputFD;
char inputFilename[MAXFILENAMELENGTH];
char outputFilename[MAXFILENAMELENGTH];
char outputFilenameBase[MAXFILENAMELENGTH];
ssize_t transfersize = 0;
ssize_t blocksize = 0;
char* transferBuffer = NULL;
ssize_t buffersize;
ssize_t bytesRead = 0;
ssize_t totalBytesRead = 0;
int totalReads = 0;
ssize_t bytesWritten = 0;
ssize_t totalBytesWritten = 0;
int totalWrites = 0;
int inputFileResets = 0;
int processes;
transfersize = DEFAULT_TRANSFERSIZE;
blocksize = DEFAULT_BLOCKSIZE;
/* Set default number of processes */
if(argc < 2){
processes = 1;
}
if(argc > 1){
processes = atol(argv[1]);
if(processes < 1){
fprintf(stderr, "Bad number of processes\n");
exit(EXIT_FAILURE);
}
}
/* Set supplied input filename or default if not supplied */
if(strnlen(DEFAULT_INPUTFILENAME, MAXFILENAMELENGTH) >= MAXFILENAMELENGTH){
fprintf(stderr, "Default input filename too long\n");
exit(EXIT_FAILURE);
}
strncpy(inputFilename, DEFAULT_INPUTFILENAME, MAXFILENAMELENGTH);
/* Set supplied output filename base or default if not supplied */
if(strnlen(DEFAULT_OUTPUTFILENAMEBASE, MAXFILENAMELENGTH) >= MAXFILENAMELENGTH){
fprintf(stderr, "Default output filename base too long\n");
exit(EXIT_FAILURE);
}
strncpy(outputFilenameBase, DEFAULT_OUTPUTFILENAMEBASE, MAXFILENAMELENGTH);
/* Confirm blocksize is multiple of and less than transfersize*/
if(blocksize > transfersize){
fprintf(stderr, "blocksize can not exceed transfersize\n");
exit(EXIT_FAILURE);
}
if(transfersize % blocksize){
fprintf(stderr, "blocksize must be multiple of transfersize\n");
exit(EXIT_FAILURE);
}
int pid = forkMe(processes);
if(pid != 0){
/* Allocate buffer space */
buffersize = blocksize;
if(!(transferBuffer = malloc(buffersize*sizeof(*transferBuffer)))){
perror("Failed to allocate transfer buffer");
exit(EXIT_FAILURE);
}
/* Open Input File Descriptor in Read Only mode */
if((inputFD = open(inputFilename, O_RDONLY | O_SYNC)) < 0){
perror("Failed to open input file");
exit(EXIT_FAILURE);
}
/* Open Output File Descriptor in Write Only mode with standard permissions*/
rv = snprintf(outputFilename, MAXFILENAMELENGTH, "%s-%d",
outputFilenameBase, getpid());
if(rv > MAXFILENAMELENGTH){
fprintf(stderr, "Output filenmae length exceeds limit of %d characters.\n",
MAXFILENAMELENGTH);
exit(EXIT_FAILURE);
}
else if(rv < 0){
perror("Failed to generate output filename");
exit(EXIT_FAILURE);
}
if((outputFD =
open(outputFilename,
O_WRONLY | O_CREAT | O_TRUNC | O_SYNC,
S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH)) < 0){
perror("Failed to open output file");
exit(EXIT_FAILURE);
}
/* Print Status */
fprintf(stdout, "Reading from %s and writing to %s\n",
inputFilename, outputFilename);
/* Read from input file and write to output file*/
do{
/* Read transfersize bytes from input file*/
bytesRead = read(inputFD, transferBuffer, buffersize);
if(bytesRead < 0){
perror("Error reading input file");
exit(EXIT_FAILURE);
}
else{
totalBytesRead += bytesRead;
totalReads++;
}
/* If all bytes were read, write to output file*/
if(bytesRead == blocksize){
bytesWritten = write(outputFD, transferBuffer, bytesRead);
if(bytesWritten < 0){
perror("Error writing output file");
exit(EXIT_FAILURE);
}
else{
totalBytesWritten += bytesWritten;
totalWrites++;
}
}
/* Otherwise assume we have reached the end of the input file and reset */
else{
if(lseek(inputFD, 0, SEEK_SET)){
perror("Error resetting to beginning of file");
exit(EXIT_FAILURE);
}
inputFileResets++;
}
}while(totalBytesWritten < transfersize);
/* Output some possibly helpfull info to make it seem like we were doing stuff */
fprintf(stdout, "Read: %zd bytes in %d reads\n",
totalBytesRead, totalReads);
fprintf(stdout, "Written: %zd bytes in %d writes\n",
totalBytesWritten, totalWrites);
fprintf(stdout, "Read input file in %d pass%s\n",
(inputFileResets + 1), (inputFileResets ? "es" : ""));
fprintf(stdout, "Processed %zd bytes in blocks of %zd bytes\n",
transfersize, blocksize);
/* Free Buffer */
free(transferBuffer);
/* Close Output File Descriptor */
if(close(outputFD)){
perror("Failed to close output file");
exit(EXIT_FAILURE);
}
/* Close Input File Descriptor */
if(close(inputFD)){
perror("Failed to close input file");
exit(EXIT_FAILURE);
}
}
return EXIT_SUCCESS;
}
