编写程序outch，程序读入一行字符，根据命令行中的参数进行不同的输入。若有以下命令行: outch -2 程序对

编写程序outch，程序读入一行字符，根据命令行中的参数进行不同的输入。若有以下命令行: outch -2 程序对

#include
#include
#include

int main(int argc, char *argv[])
{
char buffer1[1024];
char buffer2[100];
int buffer1_len;
int buffer2_len;
int out_len;

printf("Please input string:");
gets(buffer1);

printf("Please input command(usage: out -2): ");
gets(buffer2);

buffer1_len = strlen(buffer1);
buffer2_len = strlen(buffer2);

if ( buffer2_len < 6
|| strncmp(buffer2, "out ", 4) != 0
|| (buffer2[4] != '+' && buffer2[4] != '-')
|| (out_len = atoi(buffer2 + 4)) == 0
|| fabs(out_len) > buffer1_len )
{
printf("error input, will exit.\n");
return 0;
}

if ( fabs(out_len) == buffer1_len )
{
printf("result: %s\n", buffer1);
}
else if ( buffer1_len + out_len < buffer1_len )
{
printf("result: %s\n", buffer1 + buffer1_len + out_len);
}
else
{
buffer1[out_len] = '\0';
printf("result: %s\n", buffer1);
}

return 0;
}