commit 68eec1a0852cab55c6ebbfc30c58bd3041346ddc
Author: Jack-Benny Persson <jack-benny@cyberinfo.se>
Date:   Sun Jul 9 06:07:34 2017 +0200

    First commit

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..11064c6
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,8 @@
+CC=cc
+CFLAGS=-Wall -pedantic
+
+on-stock: on-stock.o
+	${CC} ${CFLAGS} on-stock.o -o on-stock
+
+clean:
+	rm -f on-stock.o on-stock
diff --git a/on-stock.c b/on-stock.c
new file mode 100644
index 0000000..5987d57
--- /dev/null
+++ b/on-stock.c
@@ -0,0 +1,287 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define FILEMAXLENGTH 50
+#define NAMEMAXLENGTH 30
+
+struct myData
+{
+    char name[NAMEMAXLENGTH];
+    int quantity;
+    float price;
+};
+
+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);
+
+int main(int argc, char* argv[])
+{
+    int numRec;
+    int create;
+    int choice;
+    int opt;
+    char filename[FILEMAXLENGTH] = "alloctest.bin";
+
+    if (argc != 2)
+    {
+	fprintf(stderr, "Usage: %s [-l] [-s] [-m [-m [-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"
+		"-r = remove a article\n"
+		"-n = create a new article\n"
+		"-f = specifiy a filename for the database\n", argv[0]);
+        return 1;
+    }
+    
+    /* Process command line arugments */
+    while ((opt = getopt(argc, argv, "lsmrnf:")) != -1)
+    {
+        switch (opt)
+	{
+        case 'l':
+	    choice = 'l';
+	    break;
+        case 's':
+	    choice = 's';
+	    break;
+        case 'm':
+	    choice = 'm';
+	    break;
+        case 'r':
+	    choice = 'r';
+	    break;
+        case 'n':
+	    choice = 'n';
+	    break;
+	case 'f':
+	    strncpy(filename, optarg, FILEMAXLENGTH-1);
+	    break;
+        default:
+            fprintf(stderr, "Usage: %s [-l] [-s] [-m [-m [-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"
+		    "-r = remove a article\n"
+		    "-n = create a new article\n"
+		    "-f = specifiy a filename for the database\n", argv[0]);
+            return 1;
+	}
+    }
+    
+
+    /* Check if file exists, if it dosen't, create it */
+    if ( access(filename, R_OK|W_OK) != 0 )
+    {
+	printf("Kan inte öppna %s\n", filename);
+	printf("Skapa filen och lägg till artiklar? (j/n): ");
+	create = getchar();
+	if ( create == 'j' )
+	{
+	    numRec = 1;
+	    struct myData *data;
+	    data = calloc(numRec, sizeof(struct myData));
+	    new(data, numRec);
+	    free(data);
+	}
+	else
+	    return 1;
+    }
+
+    struct myData *data;
+
+    if ( choice == 'l' || choice == 's' || choice == 'm' || choice == 'r' )
+    {
+	/* Open file in read-mode */
+	FILE *fp = fopen("alloctest.bin", "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 == 'r' )
+	    delete(data, numRec);
+
+    }
+    else if ( choice == 'n' )
+    {
+	data = calloc(1, sizeof(struct myData));
+	new(data, numRec);
+    }
+
+    free(data);
+    return 0;
+}
+
+void list(struct myData *datap, int numRec)
+{
+    for (int i = 0; i<numRec; i++)
+    {
+	printf("Name: %s\n", datap[i].name);
+	printf("Quantity: %d\n", datap[i].quantity);
+	printf("Price: %f\n", datap[i].price);
+	printf("\n");
+    }
+}
+
+void search(struct myData *datap, int numRec)
+{
+    char searchword[NAMEMAXLENGTH];
+    
+    printf("Name: ");
+    fgets(searchword, NAMEMAXLENGTH, stdin);
+    searchword[strcspn(searchword, "\n")] = '\0';
+    printf("\n");
+    
+    for (int i = 0; i<numRec; i++)
+    {
+	if ( strcmp(searchword, datap[i].name) != 0 )
+	    continue;
+	
+	printf("Name: %s\n", datap[i].name);
+	printf("Quantity: %d\n", datap[i].quantity);
+	printf("Price: %f\n", 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';
+    printf("\n");
+    
+    for (int i = 0; i<numRec; i++)
+    {
+	if ( strcmp(searchword, datap[i].name) == 0 )
+	{
+	    printf("Namn: %s\n", datap[i].name);
+	    printf("Quantity: %d\n", datap[i].quantity);
+	    printf("Price: %f\n", datap[i].price);
+	    printf("\n");
+
+	    printf("What do you like to modify? (name, quantity, price): ");
+	    scanf("%9s", what);
+	    if ( strcmp(what, "name") == 0 )
+	    {
+		printf("Name: "); scanf("%29s", datap[i].name);
+	    }
+	    else if ( strcmp(what, "quantity") == 0 )
+	    {
+		printf("Quantity (absolute value or +/-NUMBER: "); scanf("%19s", quant);
+		printf("Sign: %c\n", quant[0]);
+		if (quant[0] == '+')
+		    datap[i].quantity = datap[i].quantity + atoi(quant);
+		else if (quant[0] == '-')
+		{
+		    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("alloctest.bin", "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';
+    
+    printf("\n");
+    for (int i = 0; i<numRec; i++)
+    {
+	if ( strcmp(searchword, datap[i].name) == 0 )
+	{
+	    printf("Name: %s\n", datap[i].name);
+	    printf("Quantity: %d\n", datap[i].quantity);
+	    printf("Price: %f\n", datap[i].price);
+	    printf("\n");
+
+	    printf("Delete the record listed above? (y/n): ");
+	    answer = getchar();
+	    if ( answer == 'y' )
+	    {
+		FILE *newfp = fopen("alloctest.bin", "wb");
+		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);
+	    }
+	}
+	else
+	{
+	    printf("%s not found in database\n", searchword);
+	}
+    }
+}
+
+int new(struct myData *datap, int numRec)
+{
+    int bytes;
+    FILE *fp = fopen("alloctest.bin", "ab");
+    if (fp == NULL)
+    {
+	printf("Can't open file for writing\n");
+	return 1;
+    }
+
+    for (;;)
+    {
+	printf("Name: ('done' if finish) ");
+	fgets(datap->name, NAMEMAXLENGTH, stdin);
+	datap->name[strcspn(datap->name, "\n")] = '\0';
+	
+	if ( strcmp(datap->name, "klar") == 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("Kunde inte skriva till filen!\n");
+	    return 1;
+	}
+    }
+}
+
+