on-stock/on-stock.c

321 lines
7.2 KiB
C

/* A simple inventory tool written in C, by
* Jack-Benny Persson (jack-benny@cyberinfo.se).
* Released under GNU GPLv2.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/* Macros */
#define FILEMAXLENGTH 50
#define NAMEMAXLENGTH 30
/* Globals */
struct myData
{
char name[NAMEMAXLENGTH];
int quantity;
float price;
};
char filename[FILEMAXLENGTH] = "storage.bin";
/* Function prototype */
void list(struct myData *datap, int numRec);
void search(struct myData *datap, int numRec);
void modify(struct myData *datap, int numRec);
void delete(struct myData *datap, int numRec);
int new(struct myData *datap, int numRec);
void printUsage(char *arg);
void printHeader(void);
int main(int argc, char* argv[])
{
int numRec;
int create;
int choice;
int opt;
if (argc < 2)
{
printUsage(argv[0]);
return 1;
}
/* Process command line arugments */
while ((opt = getopt(argc, argv, "lsmdnf:")) != -1)
{
switch (opt)
{
case 'l':
choice = 'l';
break;
case 's':
choice = 's';
break;
case 'm':
choice = 'm';
break;
case 'd':
choice = 'd';
break;
case 'n':
choice = 'n';
break;
case 'f':
strncpy(filename, optarg, FILEMAXLENGTH-1);
break;
default:
printUsage(argv[0]);
return 1;
}
}
/* Check if file exists, if it dosen't, create it */
if ( access(filename, R_OK|W_OK) != 0 )
{
printf("Could not open %s\n", filename);
printf("Create the file and start adding records? (y/n): ");
create = getchar();
if ( create == 'y' )
{
numRec = 1;
struct myData *data;
data = calloc(numRec, sizeof(struct myData));
new(data, numRec);
free(data);
}
else
return 1;
}
/* The structure to contain our database */
struct myData *data;
/* Continue processesing the command-line arugments */
if ( choice == 'l' || choice == 's' || choice == 'm' || choice == 'd' )
{
/* Open file in read-mode */
FILE *fp = fopen(filename, "rb");
/* Read in the content from the file to the structure */
fseek(fp, 0, SEEK_END);
numRec = ftell(fp) / sizeof(struct myData);
data = calloc(numRec, sizeof(struct myData));
rewind(fp);
fread(data, sizeof(struct myData), numRec, fp);
fclose(fp);
if ( choice == 'l' )
list(data, numRec);
else if ( choice == 's' )
search(data, numRec);
else if ( choice == 'm' )
modify(data, numRec);
else if ( choice == 'd' )
delete(data, numRec);
}
else if ( choice == 'n' )
{
data = calloc(1, sizeof(struct myData));
new(data, numRec);
}
else
{
printUsage(argv[0]);
return 1;
}
free(data);
return 0;
}
void list(struct myData *datap, int numRec)
{
printHeader();
for (int i = 0; i<numRec; i++)
{
printf("%-30s\t", datap[i].name);
printf("%-10d\t", datap[i].quantity);
printf("%.2f\t", datap[i].price);
printf("\n");
}
printf("\n");
}
void search(struct myData *datap, int numRec)
{
char searchword[NAMEMAXLENGTH];
printf("Name: ");
fgets(searchword, NAMEMAXLENGTH, stdin);
/* Replace the newline character with a null character */
searchword[strcspn(searchword, "\n")] = '\0';
for (int i = 0; i<numRec; i++)
{
if ( strcmp(searchword, datap[i].name) != 0 )
continue;
printHeader();
printf("%-30s\t", datap[i].name);
printf("%-10d\t", datap[i].quantity);
printf("%.2f\t", datap[i].price);
printf("\n");
}
}
void modify(struct myData *datap, int numRec)
{
char searchword[NAMEMAXLENGTH];
char what[10];
char quant[20];
printf("Name: ");
fgets(searchword, NAMEMAXLENGTH, stdin);
searchword[strcspn(searchword, "\n")] = '\0';
for (int i = 0; i<numRec; i++)
{
if ( strcmp(searchword, datap[i].name) == 0 )
{
printHeader();
printf("%-30s\t", datap[i].name);
printf("%-10d\t", datap[i].quantity);
printf("%.2f\t", datap[i].price);
printf("\n\n");
printf("What do you like to modify? (name, quantity, price): ");
fgets(what, 10, stdin);
what[strcspn(what, "\n")] = '\0';
if ( strcmp(what, "name") == 0 )
{
printf("Name: "); scanf("%29s", datap[i].name);
}
else if ( strcmp(what, "quantity") == 0 )
{
printf("Quantity (absolute value or +/-NUMBER: ");
fgets(quant, 20, stdin);
quant[strcspn(quant, "\n")] = '\0';
/* Process the first character */
if (quant[0] == '+')
datap[i].quantity = datap[i].quantity + atoi(quant);
else if (quant[0] == '-')
{
/* We need to replace the - with a space before atoi */
quant[0] = ' ';
datap[i].quantity = datap[i].quantity - atoi(quant);
}
else
datap[i].quantity = atoi(quant);
}
else if ( strcmp(what, "price") == 0 )
{
printf("Price: "); scanf("%f", &datap[i].price);
}
}
}
FILE *newfp = fopen(filename, "wb");
fwrite(datap, sizeof(struct myData), numRec, newfp);
fclose(newfp);
}
void delete(struct myData *datap, int numRec)
{
char searchword[NAMEMAXLENGTH];
int answer;
printf("Name: ");
fgets(searchword, NAMEMAXLENGTH, stdin);
searchword[strcspn(searchword, "\n")] = '\0';
for (int i = 0; i<numRec; i++)
{
if ( strcmp(searchword, datap[i].name) == 0 )
{
printHeader();
printf("%-30s\t", datap[i].name);
printf("%-10d\t", datap[i].quantity);
printf("%.2f\t", datap[i].price);
printf("\n\n");
printf("Delete the record listed above? (y/n): ");
answer = getchar();
if ( answer == 'y' )
{
FILE *newfp = fopen(filename, "wb");
/* Write out all records, except the one we cant to delete,
back to the file, one record at a time */
for (int j = 0; j<numRec; j++)
{
if ( strcmp(searchword, datap[j].name) == 0 )
continue;
fwrite(&datap[j], sizeof(struct myData), 1, newfp);
}
fclose(newfp);
}
}
}
}
int new(struct myData *datap, int numRec)
{
int bytes;
FILE *fp = fopen(filename, "ab");
if (fp == NULL)
{
printf("Can't open file for writing\n");
return 1;
}
/* Ask for, and write out, one record at a time */
for (;;)
{
/* Clear the input buffer (from the previous iteration) */
setbuf(stdin, NULL);
printf("Name ('done' when finished): ");
fgets(datap->name, NAMEMAXLENGTH, stdin);
datap->name[strcspn(datap->name, "\n")] = '\0';
if ( strcmp(datap->name, "done") == 0 )
{
fclose(fp);
return 0;
}
printf("Quantity: "); scanf("%d", &datap->quantity);
printf("Price: "); scanf("%f", &datap->price);
bytes = fwrite(datap, sizeof(struct myData), 1, fp);
if (bytes != 1)
{
printf("Could not write to the file!\n");
return 1;
}
}
}
void printUsage(char *arg)
{
fprintf(stderr, "Usage: %s [-l] [-s] [-m [-d [-n] [-f filename]\n"
"-l = list the articles in the database\n"
"-s = search for an article in the database\n"
"-m = modify a article\n"
"-d = delete a article\n"
"-n = create a new article\n"
"-f = specifiy a filename for the database\n", arg);
}
void printHeader(void)
{
printf("\n%-30s\t", "Name");
printf("%s\t", "Quantity");
printf("%s\t\n", "Price");
for (int i = 0; i<=52; i++)
printf("=");
printf("\n");
}