create a makefile for the project

.cproject

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<?fileVersion 4.0.0?>
+
+<cproject storage_type_id="org.eclipse.cdt.core.XmlProjectDescriptionStorage">
+	<storageModule moduleId="org.eclipse.cdt.core.settings">
+		<cconfiguration id="0.1058516244">
+			<storageModule buildSystemId="org.eclipse.cdt.managedbuilder.core.configurationDataProvider" id="0.1058516244" moduleId="org.eclipse.cdt.core.settings" name="Default">
+				<externalSettings/>
+				<extensions>
+					<extension id="org.eclipse.cdt.core.VCErrorParser" point="org.eclipse.cdt.core.ErrorParser"/>
+					<extension id="org.eclipse.cdt.core.GmakeErrorParser" point="org.eclipse.cdt.core.ErrorParser"/>
+					<extension id="org.eclipse.cdt.core.CWDLocator" point="org.eclipse.cdt.core.ErrorParser"/>
+					<extension id="org.eclipse.cdt.core.GCCErrorParser" point="org.eclipse.cdt.core.ErrorParser"/>
+					<extension id="org.eclipse.cdt.core.GASErrorParser" point="org.eclipse.cdt.core.ErrorParser"/>
+					<extension id="org.eclipse.cdt.core.GLDErrorParser" point="org.eclipse.cdt.core.ErrorParser"/>
+				</extensions>
+			</storageModule>
+			<storageModule moduleId="cdtBuildSystem" version="4.0.0">
+				<configuration buildProperties="" description="" id="0.1058516244" name="Default" parent="org.eclipse.cdt.build.core.prefbase.cfg">
+					<folderInfo id="0.1058516244." name="/" resourcePath="">
+						<toolChain id="org.eclipse.cdt.build.core.prefbase.toolchain.470909688" name="No ToolChain" resourceTypeBasedDiscovery="false" superClass="org.eclipse.cdt.build.core.prefbase.toolchain">
+							<targetPlatform id="org.eclipse.cdt.build.core.prefbase.toolchain.470909688.1368504229" name=""/>
+							<builder id="org.eclipse.cdt.build.core.settings.default.builder.1033929255" keepEnvironmentInBuildfile="false" managedBuildOn="false" name="Gnu Make Builder" superClass="org.eclipse.cdt.build.core.settings.default.builder"/>
+							<tool id="org.eclipse.cdt.build.core.settings.holder.libs.913940441" name="holder for library settings" superClass="org.eclipse.cdt.build.core.settings.holder.libs"/>
+							<tool id="org.eclipse.cdt.build.core.settings.holder.1642021164" name="Assembly" superClass="org.eclipse.cdt.build.core.settings.holder">
+								<inputType id="org.eclipse.cdt.build.core.settings.holder.inType.747230842" languageId="org.eclipse.cdt.core.assembly" languageName="Assembly" sourceContentType="org.eclipse.cdt.core.asmSource" superClass="org.eclipse.cdt.build.core.settings.holder.inType"/>
+							</tool>
+							<tool id="org.eclipse.cdt.build.core.settings.holder.1979926564" name="GNU C++" superClass="org.eclipse.cdt.build.core.settings.holder">
+								<inputType id="org.eclipse.cdt.build.core.settings.holder.inType.1913423411" languageId="org.eclipse.cdt.core.g++" languageName="GNU C++" sourceContentType="org.eclipse.cdt.core.cxxSource,org.eclipse.cdt.core.cxxHeader" superClass="org.eclipse.cdt.build.core.settings.holder.inType"/>
+							</tool>
+							<tool id="org.eclipse.cdt.build.core.settings.holder.124573241" name="GNU C" superClass="org.eclipse.cdt.build.core.settings.holder">
+								<inputType id="org.eclipse.cdt.build.core.settings.holder.inType.1307115393" languageId="org.eclipse.cdt.core.gcc" languageName="GNU C" sourceContentType="org.eclipse.cdt.core.cSource,org.eclipse.cdt.core.cHeader" superClass="org.eclipse.cdt.build.core.settings.holder.inType"/>
+							</tool>
+						</toolChain>
+					</folderInfo>
+				</configuration>
+			</storageModule>
+			<storageModule moduleId="org.eclipse.cdt.core.externalSettings"/>
+		</cconfiguration>
+	</storageModule>
+	<storageModule moduleId="cdtBuildSystem" version="4.0.0">
+		<project id="string_match.null.882191851" name="string_match"/>
+	</storageModule>
+	<storageModule moduleId="scannerConfiguration">
+		<autodiscovery enabled="true" problemReportingEnabled="true" selectedProfileId=""/>
+		<scannerConfigBuildInfo instanceId="0.1058516244">
+			<autodiscovery enabled="true" problemReportingEnabled="true" selectedProfileId=""/>
+		</scannerConfigBuildInfo>
+	</storageModule>
+	<storageModule moduleId="org.eclipse.cdt.core.LanguageSettingsProviders"/>
+</cproject>

.project

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>string_match</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.cdt.managedbuilder.core.genmakebuilder</name>
+			<triggers>clean,full,incremental,</triggers>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.cdt.managedbuilder.core.ScannerConfigBuilder</name>
+			<triggers>full,incremental,</triggers>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.cdt.core.cnature</nature>
+		<nature>org.eclipse.cdt.core.ccnature</nature>
+		<nature>org.eclipse.cdt.managedbuilder.core.managedBuildNature</nature>
+		<nature>org.eclipse.cdt.managedbuilder.core.ScannerConfigNature</nature>
+	</natures>
+</projectDescription>

Makefile

@@ -0,0 +1,53 @@
+CFLAGS = -I. -Wall -g
+LDFLAGS  = 
+LIBS     =  
+
+ifeq ($(OSTYPE),linux)
+EXE =
+else
+EXE = .exe
+endif
+
+PRJECT_NAME=string_match
+
+all: $(PRJECT_NAME)$(EXE)
+
+CC=gcc
+
+.c.o: 
+	@echo [CC]: $<
+	@$(CC) $(CFLAGS) -c $< -o $@
+
+%.out:
+	@echo [OUT]: $^
+	@$(CC) $(CFLAGS) $^ $(LDFLAGS)  -o $@
+
+%.exe:
+	@echo [EXE]: $^
+	@$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(sources) $(LIBS)
+
+%.a:
+	@echo [AR]: $@
+	@ar rcs $@ $^
+
+%.d: %.c
+	@echo [DEP]: $<
+	@$(SHELL) -ec '$(CC) -MM -MQ $*.o $(CFLAGS) $< > $@'
+
+
+sources = string_util.c brute_force.c rabin_karp.c string_match.c
+
+ifneq ($(MAKECMDGOALS),mrproper)
+ifneq ($(MAKECMDGOALS),clean)
+-include $(sources:.c=.d)
+endif
+endif
+
+$(PRJECT_NAME)$(EXE): $(sources:.c=.o)
+
+.PHONY: clean mrproper
+clean:
+	rm -f *.o *.out, *$(EXE)
+
+mrproper: clean
+	rm -f *.d

README.md

@@ -0,0 +1,7 @@
+string match
+============
+
+1. Learning the github co-operate development.
+2. Learning the rabin_karp algorithm.
+
+

brute_force.c

@@ -1,18 +1,8 @@
 #include<stdio.h>
 
-/*
-  Checks if char* q starts with char* p
- */
-int strstarts(const char *p, const char *q)
-{
-  while(*p && *p == *q){
-    ++p;
-    ++q;
-  }
-  // if *p is null return true else return diff
-  return *p ? *p - *q: 0;
-}
+#include <sys/time.h>
 
+#include "string_match.h"
 /*
   Checks at each point if the needle is substring of haystack
  */
@@ -26,7 +16,7 @@ int brute_force(const char *needle, const char *haystack)
   return -1;
 }
 
-int main(int argc, char **argv)
+int brute_force_test(int argc, char **argv)
 {
 #if DEBUG
   {
@@ -40,14 +30,17 @@ int main(int argc, char **argv)
         printf("Failed to find %s in %s\n", needle, haystack);
     }
   }
-#elif
+#else
   if(argc < 3){
     printf("Usage : <command> <pattern> <string>\n");
     return 0;
   }
   int index = brute_force(argv[1], argv[2]);
   if(index >= 0)
-    printf("Found %s in %s at %d\n", argv[1], argv[2], index);
+  {
+    //printf("Found %s in %s at %d\n", argv[1], argv[2], index);
+  	printf("Found in at %d\n", index);
+  }
   else
     printf("Failed to find %s in %s\n", argv[1], argv[2]);
 #endif

rabin_karp.c

@@ -1,21 +1,13 @@
 #include<stdio.h>
 #include<string.h>
+
+#include <sys/time.h>
+
+#include "string_match.h"
+
 #define PRIME_BASE 39839
 #define MOD 40000
 
-/*
-  Checks if char* q starts with char* p
- */
-int strstarts(const char *p, const char *q)
-{
-  while(*p && *p == *q){
-    ++p;
-    ++q;
-  }
-  // if *p is null return true else return diff
-  return *p ? *p - *q: 0;
-}
-
 int hash(const char *str, int len)
 {
   int i,h;
@@ -74,7 +66,7 @@ int rabin_karp(const char *needle, const char *haystack)
     return -1;
 }
 
-int main(int argc, char **argv)
+int rabin_karp_test(int argc, char **argv)
 {
 #if DEBUG
   {
@@ -88,14 +80,17 @@ int main(int argc, char **argv)
         printf("Failed to find %s in %s\n", needle, haystack);
     }
   }
-#elif
+#else
   if(argc < 3){
     printf("Usage : <command> <pattern> <string>\n");
     return 0;
   }
   int index = rabin_karp(argv[1], argv[2]);
   if(index >= 0)
-    printf("Found %s in %s at %d\n", argv[1], argv[2], index);
+  {
+	    //printf("Found %s in %s at %d\n", argv[1], argv[2], index);
+	  	printf("Found in at %d\n", index);
+  }
   else
     printf("Failed to find %s in %s\n", argv[1], argv[2]);
 #endif

string_match.c

@@ -0,0 +1,111 @@
+/*
+ * string_match.c
+ *
+ *  Created on: 2013-7-19
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <sys/time.h>
+#include <unistd.h>
+
+#include "string_match.h"
+
+int substring_testcase1(char* sub, int sublen, char* target, int targetlen);
+int test_substringcase1(void);
+
+int main(int argc, char **argv)
+{
+	int rc;
+
+#if 1
+	rc= test_substringcase1();
+#else
+	rc= rabin_karp_test(argc, argv);
+#endif
+
+	return rc;
+}
+
+int test_substringcase1(void)
+{
+	char* sub;
+	int sublen;
+	char* target;
+	int targetlen;
+	int argc;
+	char* argv[3];
+
+	long mtime;
+	struct timeval start, end;
+
+	/**
+	 * string
+	 */
+	sublen = 1024;
+	sub = malloc (sublen);
+	if(sub == NULL)
+		return -1;
+
+	targetlen = 1024*1024;
+	target = malloc (targetlen);
+	if(target == NULL)
+	{
+		free(sub);
+		return -2;
+	}
+
+	substring_testcase1(sub, sublen, target, targetlen);
+
+	argc=3;
+	argv[0]="brute_force";
+	argv[1]=sub;
+	argv[2]=target;
+
+	printf("test with %s\n", argv[0]);
+    gettimeofday(&start, NULL);
+	brute_force_test(argc, argv );
+    gettimeofday(&end, NULL);
+    mtime=getTimeDiffer(start, end);
+	printf("done in %ld milliseconds\n", mtime);
+
+	printf("test with %s\n", argv[0]);
+    gettimeofday(&start, NULL);
+    rabin_karp_test(argc, argv );
+    gettimeofday(&end, NULL);
+    mtime=getTimeDiffer(start, end);
+	printf("done in %ld milliseconds\n", mtime);
+
+    free(target);
+	free(sub);
+
+	return 0;
+}
+
+/**
+ * patten: aaab
+ * target: aaaaaaaaaaaaaaaaaab
+ */
+int substring_testcase1(char* sub, int sublen, char* target, int targetlen)
+{
+	int i;
+
+	for(i=0;i<sublen-2;i++)
+	{
+		sub[i]='a';
+	}
+	sub[sublen-2]='b';
+	sub[sublen-1]=0;
+
+
+	for(i=0;i<targetlen-2;i++)
+	{
+		target[i]='a';
+	}
+	target[targetlen-2]='b';
+	target[targetlen-1]=0;
+
+	return 0;
+}

string_match.h

@@ -0,0 +1,22 @@
+/*
+ * string_match.h
+ *
+ *  Created on: 2013-7-19
+ */
+
+#ifndef STRING_MATCH_H_
+#define STRING_MATCH_H_
+
+extern int strstarts(const char *p, const char *q);
+extern int getTimeDiffer(struct timeval start,  struct timeval end);
+
+extern int brute_force(const char *needle, const char *haystack);
+extern int brute_force_test(int argc, char **argv);
+
+extern int hash(const char *str, int len);
+extern int rehash(int hash, char remove, char add, int maxpow);
+extern int mod_pow(int base, int pow, int mod);
+extern int rabin_karp(const char *needle, const char *haystack);
+extern int rabin_karp_test(int argc, char **argv);
+
+#endif /* STRING_MATCH_H_ */