From 113c5910946f7893bdaf576f0a870c2e58d8be84 Mon Sep 17 00:00:00 2001
From: Jack-Benny Persson <jack-benny@cyberinfo.se>
Date: Thu, 9 Nov 2017 06:15:57 +0100
Subject: [PATCH] Re-wrote most of the program, last version was a mess

---
 on-stock.c | 361 ++++++++++++++++++++++-------------------------------
 1 file changed, 151 insertions(+), 210 deletions(-)

diff --git a/on-stock.c b/on-stock.c
index ec4d972..1d4363f 100644
--- a/on-stock.c
+++ b/on-stock.c
@@ -1,15 +1,15 @@
 /* A simple inventory tool written in C, by
- * Jack-Benny Persson (jack-benny@cyberinfo.se).
- * Released under GNU GPLv2.
+   Jack-Benny Persson (jack-benny@cyberinfo.se).
+   Released under GNU GPLv2.
 */
 
+#define _XOPEN_SOURCE 500
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 /* Macros */
-#define FILEMAXLENGTH 50
 #define NAMEMAXLENGTH 30
 
 /* Globals */
@@ -20,12 +20,12 @@ struct myData
     float price;
 };
 
-char filename[FILEMAXLENGTH] = "storage.bin";
+char filename[] = "storage.bin";
 
-/* Function prototype */
+/* Function prototypes */
 void list(struct myData *datap, int numRec);
 void search(struct myData *datap, int numRec, char *name);
-void modify(struct myData *datap, int numRec, char *name, char *num);
+void modify(struct myData *datap, int numRec, char *name);
 void delete(struct myData *datap, int numRec, char *name);
 int new(struct myData *datap, int numRec);
 void printUsage(char *arg);
@@ -34,39 +34,67 @@ void printHeader(void);
 
 int main(int argc, char* argv[])
 {
+    FILE *fp; 
+    int newart = 0;
     int numRec;
     int create;
-    int choice;
     int opt;
 
+    struct myData *data;
+
+    /* Print help and exit if no arguments are given */
     if (argc < 2)
     {
         printUsage(argv[0]);
         return 1;
     }
     
-    /* Process command line arugments */
-    while ((opt = getopt(argc, argv, "hlsmdnf:")) != -1)
+    /* Check file access mode */
+    if ( access(filename, R_OK|W_OK) != 0 )
+    {
+        fprintf(stderr, "Could not open %s\n", filename);
+        printf("Create the file and start adding records? (y/n): ");
+        create = getchar();
+        if ( create == 'y' )
+        {
+        /* Start createing records */
+            numRec = 1;
+            data = calloc(numRec, sizeof(struct myData));
+            new(data, numRec);
+            free(data);
+        }
+        else
+            return 1;
+    }
+
+    fp = fopen(filename, "rb");
+
+    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);
+
+    /* Process arguments with getopt() */
+    while ((opt = getopt(argc, argv, "hls:m:d:n")) != -1)
     {
         switch (opt)
         {
         case 'l':
-            choice = 'l';
+            list(data, numRec);
             break;
         case 's':
-            choice = 's';
+            search(data, numRec, optarg);
             break;
         case 'm':
-            choice = 'm';
+            modify(data, numRec, optarg);
             break;
         case 'd':
-            choice = 'd';
+            delete(data, numRec, optarg);
             break;
         case 'n':
-            choice = 'n';
-            break;
-        case 'f':
-            strncpy(filename, optarg, FILEMAXLENGTH-1);
+            newart = 1;
             break;
         case 'h':
             printUsage(argv[0]);
@@ -77,79 +105,24 @@ int main(int argc, char* argv[])
         }
     }
     
-
-    /* Check if file exists, if it dosen't, create it */
-    if ( access(filename, R_OK|W_OK) != 0 )
-    {
-        fprintf(stderr, "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' && argc >= 2 )
-            search(data, numRec, argv[2]);
-        else if ( choice == 's' && argc <= 2)
-            search(data, numRec, NULL);
-        else if ( choice == 'm' && argc >= 3)
-            modify(data, numRec, argv[2], argv[3]);
-        else if ( choice == 'm' && argc <= 4)
-            modify(data, numRec, NULL, NULL);
-        else if ( choice == 'd' && argc >= 2 )
-            delete(data, numRec, argv[2]);
-        else if ( choice == 'd' && argc <= 2 )
-            delete(data, numRec, NULL);
-
-    }
-    else if ( choice == 'n' )
+    /* Continue here */
+    if ( newart == 1 )
     {
         data = calloc(1, sizeof(struct myData));
         if ( new(data, numRec) == 1 )
             return 1;
     }
-    else
-    {
-        printUsage(argv[0]);
-        return 1;
-    }
 
+    /* Finished */
     free(data);
     return 0;
 }
 
-
 void list(struct myData *datap, int numRec)
 {
+    int i;
     printHeader();
-    for (int i = 0; i<numRec; i++)
+    for (i = 0; i<numRec; i++)
     {
         printf("%-30s\t", datap[i].name);
         printf("%-10d\t", datap[i].quantity);
@@ -161,22 +134,11 @@ void list(struct myData *datap, int numRec)
 
 void search(struct myData *datap, int numRec, char *name)
 {
-    char searchword[NAMEMAXLENGTH];
-    if (name != NULL)
+    int i;
+    /* Iterate over the database and search */
+    for (i = 0; i<numRec; i++)
     {
-        strncpy(searchword, name, NAMEMAXLENGTH-1);
-    }
-    else
-    {
-        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 )
+        if ( strcmp(name, datap[i].name) != 0 )
             continue;
         printHeader();
         printf("%-30s\t", datap[i].name);
@@ -186,66 +148,55 @@ void search(struct myData *datap, int numRec, char *name)
     }
 }
 
-void modify(struct myData *datap, int numRec, char *name, char *num)
+void modify(struct myData *datap, int numRec, char *name)
 {
-    char searchword[NAMEMAXLENGTH];
+    FILE *newfp;
+    int i;
+    int match = 0;
     char what[10];
     char quant[20];
-    int interactive = 1;
-    
-    if (name != NULL && num != NULL)
-    {
-        strncpy(searchword, name, NAMEMAXLENGTH-1);
-        strncpy(what, "quantity", 9);
-        strncpy(quant, num, 19);
-        interactive = 0;
-    }
-    else
-    {
-        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 )
-        {
-            if (interactive == 1)
-            {
-                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';
-            }
+    /* Iterate over the database and search */
+    for (i = 0; i<numRec; i++)
+    {
+        if ( strcmp(name, datap[i].name) == 0 )
+        {
+            match = 1;
+            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);
+                printf("Name: ");
+                fgets(datap[i].name, NAMEMAXLENGTH, stdin);
+                datap[i].name[strcspn(datap[i].name, "\n")] = '\0';
             }
             else if ( strcmp(what, "quantity") == 0 )
             {
-                if (interactive == 1)
+                printf("Quantity (absolute value or "
+                       "(a)dd/(s)ubtractNUMBER): ");
+                fgets(quant, 20, stdin);
+                quant[strcspn(quant, "\n")] = '\0';
+                
+                if (quant[0] == 'a') /* a for add */
                 {
-                    printf("Quantity (absolute value or (a)dd/(s)ubtractNUMBER): ");
-                    fgets(quant, 20, stdin);
-                    quant[strcspn(quant, "\n")] = '\0';
+                    quant[0] = ' '; /* Remove the sign */
+                    datap[i].quantity = datap[i].quantity +
+                        atoi(quant);
                 }
-                /* Process the first character */
-                if (quant[0] == 'a')
-                {
-                    quant[0] = ' '; /* We need to remove the character first */
-                    datap[i].quantity = datap[i].quantity + atoi(quant);
-                }
-                else if (quant[0] == 's')
+                else if (quant[0] == 's') /* s for subtract */
                 {
                     quant[0] = ' ';
-                    datap[i].quantity = datap[i].quantity - atoi(quant);
+                    datap[i].quantity = datap[i].quantity -
+                        atoi(quant);
                 }
                 else
                     datap[i].quantity = atoi(quant);
@@ -256,87 +207,84 @@ void modify(struct myData *datap, int numRec, char *name, char *num)
                 printf("Price: "); scanf("%f", &datap[i].price);
             } 
         }
-        else
-        {
-            fprintf(stderr, "Could not find %s in database\n", searchword);
-            exit(1);
-        }
-        
     }
-    FILE *newfp = fopen(filename, "wb");
+    if (match == 0)
+    {
+        fprintf(stderr, "Could not find %s in database\n", name);
+        exit(1);
+    }
+    /* Write out the new content to file */
+    if ( (newfp = fopen(filename, "wb")) == 0 )
+    {
+        fprintf(stderr, "Could not open file for writing\n");
+        exit(1);
+    }
     fwrite(datap, sizeof(struct myData), numRec, newfp);
     fclose(newfp);
 }
 
 void delete(struct myData *datap, int numRec, char *name)
 {
-    char searchword[NAMEMAXLENGTH];
+    int i, j;
+    int match = 0;
+    FILE *newfp; 
     int answer;
-    int interactive = 1;
-    
-    if (name != NULL)
-    {
-        strncpy(searchword, name, NAMEMAXLENGTH-1);
-        interactive = 0;
-        answer = 'y';
-    }
-    else
-    {
-        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 )
-        {
-            if (interactive == 1)
-            {
-                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();
-            }
+    /* Iterate the database and search */
+    for (i = 0; i<numRec; i++)
+    {
+        if ( strcmp(name, datap[i].name) == 0 )
+        {
+            match = 1;
+            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 ( (newfp = fopen(filename, "wb")) == 0 )
                 {
-                    if ( strcmp(searchword, datap[j].name) == 0 )
+                    fprintf(stderr,
+                            "Could not open file for writing\n");
+                    exit(1);
+                }
+        /* Iterate the database and write out every
+                   record except those that matched! */
+                for (j = 0; j<numRec; j++)
+                {
+                    if ( strcmp(name, datap[j].name) == 0 )
                         continue;
-                    fwrite(&datap[j], sizeof(struct myData), 1, newfp);
+                    fwrite(&datap[j], sizeof(struct myData), 1,
+                           newfp);
                 }
                 fclose(newfp);
             }
         }
-        else
-        {
-            fprintf(stderr, "Could not find %s in database\n", searchword);
-            exit(1);
-        }
+    }
+    if (match == 0)
+    {
+        fprintf(stderr, "Could not find %s in database\n", name);
+        exit(1);
     }
 }
 
 int new(struct myData *datap, int numRec)
 {
+    FILE *fp;
     int bytes;
-    FILE *fp = fopen(filename, "ab");
-    if (fp == NULL)
+    if ( (fp = fopen(filename, "ab")) == 0 )
     {
-        printf("Can't open file for writing\n");
+        fprintf(stderr, "Could not open file for writing\n");
         return 1;
     }
 
-    /* Ask for, and write out, one record at a time */
+    /* End loop when user types 'done' */
     for (;;)
     {
-        /* Clear the input buffer (from the previous iteration) */
         setbuf(stdin, NULL);
         printf("Name ('done' when finished): ");
         fgets(datap->name, NAMEMAXLENGTH, stdin);
@@ -360,33 +308,26 @@ int new(struct myData *datap, int numRec)
 
 void printUsage(char *arg)
 {
-    fprintf(stderr, "Usage: %s [-l] [-s [name]] [-m [name (a/s)quantity]]\n" 
-                     "[-d [name]] [-n] [-h] [-f filename]\n\n"
-        "-l = list the articles in the database\n"
-        "-s = search for an article in the database\n"
-        "     If no name is given as argument, you will be prompted for a name.\n"
-        "-m = modify a article\n"
-        "     If no name is given as argument, you will be prompted for a\n"
-        "     name. You'll then have the choice to change name, quantity and price.\n"
-        "     If a name is given as argument, the quantity can be changed from the\n"
-        "     command line, such as subtracting the stock by three:\n"
-        "     ./on-stock -m 'Nailgun' s3\n"
-        "-d = delete a article\n"
-        "     If no name is given as argument, you will be prompted for an article\n"
-        "     to delete.\n"
-        "     If a name is given as argument, no confirmation will be required to\n"
-        "     delete the article from the database.\n"
-        "-n = create new articles (interactive mode only)\n"
-        "-h = display this help message\n"
-        "-f = specifiy a filename for the database\n", arg);
+    fprintf(stderr, "Usage: %s [-l] [-s name]"
+            "[-m name \n" 
+            "[-d name] [-n] [-h] [-f filename]\n\n"
+        "-l      = list the articles in the database\n"
+        "-s name = search for an 'name' in the database\n"
+        "-m name = modify the article named 'name' in the database\n"
+        "     You'll then have the choice to change name, quantity "
+            "and price.\n"
+        "-d name = delete the article named 'name'\n"
+        "-n      = create new articles (interactive mode only)\n"
+        "-h      = display this help message\n", arg);
 }
 
 void printHeader(void)
 {
+    int i;
     printf("\n%-30s\t", "Name");
     printf("%s\t", "Quantity");
     printf("%s\t\n", "Price");
-    for (int i = 0; i<=52; i++)
+    for (i = 0; i<=52; i++)
         printf("=");
     printf("\n");
 }