LINUX下C语言编程怎么打印日志

将日志写到文件中去，在到文件中去看日志

例如：

int

mig_log(fmt,va_alist)

char

*fmt

va_dcl

{

va_list

ap

FILE

*fp

char

log_file[81]

struct

tm

*p_tm

time_t

clock

ap=(char

*)&va_alist

time(&clock)

p_tm=localtime(&clock)

sprintf(log_file,"%s/mig_%4d%.2d%.2d.log",

getenv("HOME"),

p_tm->tm_year+1900,

p_tm->tm_mon+1,

p_tm->tm_mday)

fp=fopen(log_file,"at")

if(fp==(FILE

*)0)

{

fprintf(stderr,"mig_err_log():can't

open

the

file

%s

!\n",log_file)

return

}

fprintf(fp,"%.2d/%.2d/%4d

%.2d:%.2d:%.2d

",

p_tm->tm_mon+1,\

p_tm->tm_mday,\

p_tm->tm_year+1900,\

p_tm->tm_hour,\

p_tm->tm_min,\

p_tm->tm_sec)

vfprintf(fp,fmt,ap)

fclose(fp)

}

这个就是写日志的函数

你这样调用：mig_log("日志开始[%s]->[%d]\n",__FILE__,__LINE__)

mig_log("日志开始!\n")都可以的

用我写的吧 实测过了的 可以直接使用

void WriteSysLog(char *str)

{

char buf[512]

long MAXLEN = 10*1024*1024//10MB

time_t timep

FILE *fp = NULL

struct tm *p

time(&timep)

p = localtime(&timep)

memset(buf,0,sizeof(buf))

sprintf(buf,"%d-%d-%d %d:%d:%d : ",(1900+p->tm_year),(1+p->tm_mon),\

p->tm_mday,p->tm_hour, p->tm_min, p->tm_sec)//星期p->tm_wday

strcat(buf,str)

strcat(buf,"\r\n")

fp = fopen("./syslog.log","r")

if(fp==NULL)

{

fp = fopen("./syslog.log","w+")

}

else

{

fseek(fp,0,2)

if(ftell(fp) >= MAXLEN)

{

fclose(fp)

fp = fopen("./syslog.log","w+")

//大于10MB则清空原日志文件

}

else

{

fclose(fp)

fp = fopen("./syslog.log","a")

}

}

fwrite(buf,1,strlen(buf),fp)

fflush(fp)

fsync(fileno(fp))

fclose(fp)

}

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