diff --git a/.gitignore b/.gitignore index 6372ebf..8ed1cb2 100644 --- a/.gitignore +++ b/.gitignore @@ -8,6 +8,8 @@ ex14 ex15 ex16 ex17 +ex17-* +!ex17-*.c ex18 ex19 ex20 diff --git a/ex17-ec1.c b/ex17-ec1.c new file mode 100644 index 0000000..aa360cb --- /dev/null +++ b/ex17-ec1.c @@ -0,0 +1,201 @@ +#include +#include +#include +#include +#include + +#define MAX_DATA 512 +#define MAX_ROWS 100 + +struct Address { + int id; + int set; + char name[MAX_DATA]; + char email[MAX_DATA]; +}; + +struct Database { + struct Address rows[MAX_ROWS]; +}; + +struct Connection { + FILE *file; + struct Database *db; +}; + +void Database_close(struct Connection *conn); + +void die(struct Connection *conn, const char *message) +{ + if(errno) { + perror(message); + } else { + printf("ERROR: %s\n", message); + } + + Database_close(conn); + exit(1); +} + +void Address_print(struct Address *addr) +{ + printf("%d %s %s\n", + addr->id, addr->name, addr->email); +} + +void Database_load(struct Connection *conn) +{ + int rc = fread(conn->db, sizeof(struct Database), 1, conn->file); + if(rc != 1) die(conn, "Failed to load database."); +} + +struct Connection* Database_open(const char *filename, char mode) +{ + struct Connection *conn = malloc(sizeof(struct Connection)); + if(!conn) die(NULL, "Memory error"); + + conn->db = malloc(sizeof(struct Database)); + if(!conn->db) die(conn, "Memory error"); + + if(mode == 'c') { + conn->file = fopen(filename, "w"); + } else { + conn->file = fopen(filename, "r+"); + + if(conn->file) { + Database_load(conn); + } + } + + if(!conn->file) die(conn, "Failed to open the file"); + + return conn; +} + +void Database_close(struct Connection *conn) +{ + if(conn) { + if(conn->file) fclose(conn->file); + if(conn->db) free(conn->db); + free(conn); + } +} + +void Database_write(struct Connection *conn) +{ + rewind(conn->file); + + int rc = fwrite(conn->db, sizeof(struct Database), 1, conn->file); + if(rc != 1) die(conn, "Failed to write database."); + + rc = fflush(conn->file); + if(rc == -1) die(conn, "Cannot flush database."); +} + +void Database_create(struct Connection *conn) +{ + int i = 0; + + for(i = 0; i < MAX_ROWS; i++) { + // make a prototype to initialize it + struct Address addr = {.id = i, .set = 0}; + // then just assign it + conn->db->rows[i] = addr; + } +} + +void Database_set(struct Connection *conn, int id, const char *name, const char *email) +{ + struct Address *addr = &conn->db->rows[id]; + if(addr->set) die(conn, "Already set, delete it first"); + + addr->set = 1; + // WARNING: bug, read the "How To Break It" and fix this + char *res = strncpy(addr->name, name, MAX_DATA); + // demonstrate the strncpy bug + if(!res) die(conn, "Name copy failed"); + + res = strncpy(addr->email, email, MAX_DATA); + if(!res) die(conn, "Email copy failed"); +} + +void Database_get(struct Connection *conn, int id) +{ + struct Address *addr = &conn->db->rows[id]; + + if(addr->set) { + Address_print(addr); + } else { + die(conn, "ID is not set"); + } +} + +void Database_delete(struct Connection *conn, int id) +{ + struct Address addr = {.id = id, .set = 0}; + conn->db->rows[id] = addr; +} + +void Database_list(struct Connection *conn) +{ + int i = 0; + struct Database *db = conn->db; + + for(i = 0; i < MAX_ROWS; i++) { + struct Address *cur = &db->rows[i]; + + if(cur->set) { + Address_print(cur); + } + } +} + +int main(int argc, char *argv[]) +{ + if(argc < 3) die(NULL, "USAGE: ex17 [action params]"); + + char *filename = argv[1]; + char action = argv[2][0]; + struct Connection *conn = Database_open(filename, action); + int id = 0; + + if(argc > 3) id = atoi(argv[3]); + if(id >= MAX_ROWS) die(conn, "There's not that many records."); + + switch(action) { + case 'c': + Database_create(conn); + Database_write(conn); + break; + + case 'g': + if(argc != 4) die(conn, "Need an id to get"); + + Database_get(conn, id); + break; + + case 's': + if(argc != 6) die(conn, "Need id, name, email to set"); + + Database_set(conn, id, argv[4], argv[5]); + Database_write(conn); + break; + + case 'd': + if(argc != 4) die(conn, "Need id to delete"); + + Database_delete(conn, id); + Database_write(conn); + break; + + case 'l': + Database_list(conn); + break; + default: + die(conn, "Invalid action, only: c=create, g=get, s=set, d=del, l=list"); + } + + Database_close(conn); + + return 0; +} diff --git a/test.sh b/test.sh new file mode 100644 index 0000000..7a580f2 --- /dev/null +++ b/test.sh @@ -0,0 +1,35 @@ +EXIT_CODE=0 +ASSERT_COUNT=0 + + +function assert_equal(){ + if [[ $1 == $2 ]] ; then + echo -n "." + else + echo -n "F" + EXIT_CODE=1 + fi + ASSERT_COUNT=$(expr $ASSERT_COUNT + 1) +} + + +function assert_not_equal(){ + if [[ $1 != $2 ]] ; then + echo -n "." + else + echo -n "F" + EXIT_CODE=1 + fi + ASSERT_COUNT=$(expr $ASSERT_COUNT + 1) +} + + +function test_finish(){ + echo + if [ $EXIT_CODE -eq 0 ]; then + echo "PASS" + else + echo "FAIL" + fi + exit $EXIT_CODE +} diff --git a/test_ex17.sh b/test_ex17.sh new file mode 100755 index 0000000..2619301 --- /dev/null +++ b/test_ex17.sh @@ -0,0 +1,55 @@ +#!/bin/bash + +source './test.sh' + +prog=${1-'./ex17'} +test_db=db.$$.$RANDOM.dat + +# ---------------------------------------------------------------------------- + +$prog 2>&1 >/dev/null +assert_equal $? 1 + +$prog $test_db c 2>&1 >/dev/null +assert_equal $? 0 + +$prog $test_db s 2>&1 >/dev/null +assert_equal $? 1 + +$prog $test_db s 1 ham ham@foo.bar +assert_equal $? 0 +$prog $test_db s 2 derp derp@foo.bar +assert_equal $? 0 +$prog $test_db s 3 herp herp@foo.bar +assert_equal $? 0 +$prog $test_db s 4 zap zap@foo.bar +assert_equal $? 0 + +$prog $test_db l > $$.out +grep '1 ham ham@foo.bar' $$.out >/dev/null +assert_equal $? 0 +$prog $test_db l > $$.out +grep '2 derp derp@foo.bar' $$.out >/dev/null +assert_equal $? 0 +$prog $test_db l > $$.out +grep '3 herp herp@foo.bar' $$.out >/dev/null +assert_equal $? 0 +$prog $test_db l > $$.out +grep '4 zap zap@foo.bar' $$.out >/dev/null +assert_equal $? 0 + +$prog $test_db g 1 > $$.out +grep '1 ham ham@foo.bar' $$.out >/dev/null +assert_equal $? 0 + +$prog $test_db d 1 +$prog $test_db l > $$.out +grep 'ham@foo.bar' $$.out >/dev/null +assert_not_equal $? 0 + +# ---------------------------------------------------------------------------- + +rm -f $$.out +rm -f $test_db + +test_finish