怎样用C语言实现删除一个文件中的重复的字符窜

用C语言写个文字处理工具把以下文件里面每行中含有“drive”或“receive”或“detector”的所在行中双引号里面的那个NODE名字提取出来存到一个文件中.在下面已有的C程序基础上添加一些代码,怎么才能把存取的文件里面相同的NODE名字删掉,只保留一个.

文件：


!!!! 10 0 1 1460031171 0000
global
relay
wire "GND" to 21850 general
wire "RSP_IM_SENSE_L" to 21851 general
end relay


test analog "c723"

wire "LIU_TX_TIP_P1" to 21773 s
wire "LIU_TX_TIP_AC_P1" to 221148 i
end test

test analog "c724"

wire "LIU_TX_TIP_P3" to 221174 s
wire "LIU_TX_TIP_AC_P3" to 22254 i
end test

test analog "c725"

wire "LIU_TX_TIP_P6" to 222155 s alternate
wire "LIU_TX_TIP_AC_P6" to 22255 i
end test



test analog "t6%jp21"

wire "TX_RING_P42" to 221109 s
wire "TX_TIP_P42" to 220108 i
end test

test analog "t6%jp22"

wire "TX_RING_P41" to 219105 s
wire "TX_TIP_P41" to 22008 i
end test

test analog "t6%jp23"

wire "RX_RING_P41" to 216105 s
wire "RX_TIP_P41" to 21705 i alternate
end test


subtest "VP1P0"
wire "VP1P0" to 21513 detector high
wire "GND" to 21955 detector low
end subtest

subtest "VP0P75"
wire "VP0P75" to 210136 detector high
wire "GND" to 21064 detector low
end subtest

subtest "1V8_AD9554"
wire "1V8_AD9554" to 20813 detector high
wire "GND" to 21064 detector low
end subtest


test analog "u2333"
functional

subtest "Pin1_offset"
wire "CLK_19M44_TCXO_REF_P" to 20734 detector high
wire "GND" to 21064 detector low
end subtest

subtest "Pin1"
wire "CLK_19M44_TCXO_REF_P" to 20734 receive frequency
end subtest
end test

test analog "y3"
functional

wire "CLK_20M_TCXO" to 214134 receive frequency
end test



test digital "u1"
timing module 2
clock internal

wire "IM_I2C_INT_OUT_L" to 20955 drive
wire "IM_I2C_SCL" to 208137 drive
wire "IM_I2C_SDA" to 20837 drive
wire "QUACK_RESET_L" to 20834 drive
wire "RSP0_I2C_SCL" to 207149 drive
wire "RSP0_I2C_SDA" to 208148 drive
wire "RSP1_I2C_SCL" to 20747 drive
wire "RSP1_I2C_SDA" to 20744 drive
wire "RSP_IM_MUX_RST_L" to 20727 drive
wire "IM_I2C_SCL" to 208137 receive
wire "IM_I2C_SDA" to 20837 receive
wire "RSP0_I2C_INT_L" to 20753 receive
wire "RSP0_I2C_SDA" to 208148 receive
wire "RSP1_I2C_INT_L" to 20951 receive
wire "RSP1_I2C_SDA" to 20744 receive
end test

test digital "u3"
timing module 2
clock internal

wire "$12N395" to 21048 drive
wire "BOARD_I2C_SCL" to 21041 drive
wire "FPGA_SPI_CS_L" to 20947 drive
wire "FPGA_SPI_HOLD_L" to 20538 drive
wire "FPGA_SPI_MOSI" to 20841 drive
wire "FPGA_SPI_SCLK" to 20838 drive
wire "FPGA_SPI_WP_L" to 21127 drive
wire "FPGA_SPI_MISO_ST" to 20842 receive
end test



已有的C程序:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main()
{
FILE *fp1;
FILE *fp2;
fp1=fopen("src.txt","r");
fp2=fopen("生成.txt","w");
if(NULL==fp1)
{
printf("未发现原文件!!!\n");
exit(-1);
}
if(NULL==fp2)
{
printf("目标文件打开失败!!!\n");
exit(-1);
}
const char* Key[] = {"drive","receive","detector"};
char buf[1024] = {0};
char* p1 = NULL;
char* p2 = NULL;
int i;
while(!feof( fp1 ) )
{
memset(buf,0,sizeof(buf));
fgets(buf,sizeof(buf)-1,fp1);
for(i=0;i < sizeof(Key)/sizeof(char*);++i)
{
p1=strstr(buf,Key[i]);//对比关键字是否存在
if(NULL != p1)
{
p1 = strstr(buf,"\"");//查找第一个引号
if(NULL != p1)
{
p2 = strstr(++p1,"\"");
if(NULL != p2)
{
*p2 = '\0';
fprintf(fp2,"%s\n",p1);
}
}
}
}
}
fclose(fp1);
fclose(fp2);
return 0;
}