我正在尝试为TCP服务器中的客户端分配名称，但是strcpy()函数给我一个分段错误。
struct clients{
int client_fd;
char* name;
struct clients* next;
}
struct clients* first;
first->client_fd = 1;
first->name = NULL;
memset(&first->name, 0, sizeof(first->name));
first->name = (char*)malloc(100*sizeof(char));
strcpy(first->name, "User");
first->next = NULL;
答案 0 :(得分：5)
指针struct clients* first;并不指向任何malloc d内存，因此尝试像first->client_id = 1这样访问其上的属性是未初始化的指针取消引用。
由于取消引用后行为未定义，因此可能在strcpy（或其他任何地方，但strcpy不是罪魁祸首）处发生分段错误。考虑使用valgrind之类的工具在发生这些非法内存访问时对其进行识别。
还
行：
first->name = NULL;
memset(&first->name, 0, sizeof(first->name));
实际上并没有做任何事情，因为first->name存储位置随后被覆盖。您可以忽略这些。
(char*)malloc(100*sizeof(char));可以是malloc(5)。 sizeof(char)保证为1个字节，(char *)是不必要的强制转换，并且100对于"User"来说是太多的内存，free仅需要5个字符（一个为空终止符） 。malloc分配了内存以避免泄漏。malloc的返回值以确保成功分配内存是一个好主意。strdup代替strcpy / strdup对，但是这样做的缺点是您可能会忘记#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct clients {
int client_fd;
char* name;
struct clients* next;
};
int main(void) {
struct clients* first = malloc(sizeof(*first));
first->client_fd = 1;
first->name = malloc(5);
strcpy(first->name, "User");
first->next = NULL;
printf("%d %s\n", first->client_fd, first->name); // => 1 User
free(first->name);
free(first);
return 0;
}
分配的内存需要释放。 这是一个重写：
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xmlns:jpa="http://www.springframework.org/schema/data/jpa" xmlns:sec="http://www.springframework.org/schema/security"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:cache="http://www.springframework.org/schema/cache"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd">
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org.apache.fineract.commands.*,
org.apache.fineract.accounting.*,
org.apache.fineract.infrastructure.*,
org.apache.fineract.scheduledjobs.*,
org.apache.fineract.organisation.*,
org.apache.fineract.portfolio.loanaccount.*,
org.apache.fineract.portfolio.savings.*,
org.apache.fineract.portfolio.*,
org.apache.fineract.useradministration.*,
org.apache.fineract.mix.*,
org.apache.fineract.template.*,
org.apache.fineract.template.service,
org.apache.fineract.batch">
<context:exclude-filter expression="org.springframework.stereotype.Controller"
type="annotation" />
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<context:exclude-filter expression="org.springframework.context.annotation.Configuration"
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<bean id="auditorAware"
class="org.apache.fineract.infrastructure.core.domain.AuditorAwareImpl" />
<jpa:auditing auditor-aware-ref="auditorAware" />
<jpa:repositories base-package="org.apache.fineract.commands.domain" />
<jpa:repositories base-package="org.apache.fineract.infrastructure.*.domain" />
<jpa:repositories base-package="org.apache.fineract.accounting.*.domain" />
<jpa:repositories base-package="org.apache.fineract.useradministration.domain" />
<jpa:repositories base-package="org.apache.fineract.organisation.*.domain" />
<jpa:repositories base-package="org.apache.fineract.portfolio.*" />
<jpa:repositories base-package="org.apache.fineract.mix.domain" />
<jpa:repositories base-package="org.apache.fineract.scheduledjobs.*" />
<jpa:repositories base-package="org.apache.fineract.template.domain" />
<import resource="infrastructure.xml" />
<import resource="securityContext.xml" />
<import resource="cache.xml" />
<bean id="applicationEventMulticaster" class="org.springframework.context.event.SimpleApplicationEventMulticaster">
<property name="taskExecutor">
<bean class="org.springframework.core.task.SimpleAsyncTaskExecutor"/>
</property>
</bean>
<import resource="spmContext.xml"/>
</beans>