unknown delete ？

[J1n-CH1na]

1. I add ens33 successfully
2. I add ens34 successfully
3. But the configuration of ens34 is deleted when modify ens33 ~

USEFUL AWK ~~~

root@ubuntu:~/Desktop/Network-Interfaces-Script-master# awk -f changeInterface.awk /etc/network/interfaces device=ens33 action=add mode=static address=192.168.239.149 netmask=255.255.255.0 gateway=192.168.239.254
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto ens33
iface ens33 inet static
    address 192.168.239.149
    netmask 255.255.255.0
    gateway 192.168.239.254

root@ubuntu:~/Desktop/Network-Interfaces-Script-master# awk -f changeInterface.awk /etc/network/interfaces device=ens34 action=add mode=static address=192.168.1.1 netmask=255.255.255.0
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto ens33
iface ens33 inet static
	address 192.168.239.149
	netmask 255.255.255.0
	gateway 192.168.239.254
auto ens34
iface ens34 inet static
    netmask 255.255.255.0
    address 192.168.1.1

root@ubuntu:~/Desktop/Network-Interfaces-Script-master# awk -f changeInterface.awk /etc/network/interfaces device=ens33 action=add mode=static address=192.168.239.149 netmask=255.255.255.0 gateway=192.168.239.254
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto ens33
iface ens33 inet static
    address 192.168.239.149
    netmask 255.255.255.0
    gateway 192.168.239.254

[J1n-CH1na]

I will see it when I'm free ~

[J1n-CH1na]

I'm done with C code~
But it has some disadvantages.

1.complex
2.can't keep old commit
3.just support ubuntu "/etc/network/interfaces" now.

follow code~

[J1n-CH1na]

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
typedef struct INTERFACE_NODE{
    char name[32];
    char mode[32];
    char address[32];
    char netmask[32];
    char gateway[32];
    struct INTERFACE_NODE* next;
}INTERFACE_NODE;

typedef struct INTERFACE_HEAD{
    int num;
    char osType[64];
    struct INTERFACE_NODE* fin;
}INTERFACE_HEAD;

struct INTERFACE_HEAD* create_interface_head(char* osType){
	struct INTERFACE_HEAD* ih = (struct INTERFACE_HEAD*)malloc(sizeof(struct INTERFACE_HEAD));
	ih->num = 0;
	strncpy(ih->osType,osType,strlen(osType));
	ih->fin = NULL;
	return ih;
}

struct INTERFACE_NODE* create_interface_node(){
	struct INTERFACE_NODE* in = (struct INTERFACE_NODE*)malloc(sizeof(struct INTERFACE_NODE));
	bzero(in->name,32);
	bzero(in->mode,32);
	bzero(in->address,32);
	bzero(in->netmask,32);
	bzero(in->gateway,32);
	in->next = NULL;
	return in;
}

int add_interface_node(struct INTERFACE_HEAD* ih,struct INTERFACE_NODE* in){
    int res = -1;
    do {
        struct INTERFACE_NODE *p = ih->fin;
        struct INTERFACE_NODE *q = in;
        if (q == NULL){
            res = -1;
            break;
        }
        if (p == NULL){
            p = q;
            ih->fin = p;
            ih->num++;
            res = 0;
            break;
        }
        while(p){
            if (p->next == NULL){
                p->next = q;
                ih->num++;
                res = 0;
                break;
            }
            p = p->next;
        }
    }while(0);
    return res;
}

int free_interface_node(struct INTERFACE_NODE* in){
	if (in != NULL){
		bzero(in->name,32);
		bzero(in->mode,32);
		bzero(in->address,32);
		bzero(in->netmask,32);
		bzero(in->gateway,32);	
		in->next = NULL;
		free(in);
	}
	in = NULL;
	return 0;
}

int traverse_interface(struct INTERFACE_HEAD* ih){
	struct INTERFACE_NODE* p = ih->fin;
	printf("=============================================\n");
	printf(" name \t mode \t address \t netmask \t gateway \n");

	while(p){
        	printf(" %s  %s  %s  %s  %s\n",p->name,p->mode,p->address,p->netmask,p->gateway);
		p = p->next;
	}

	printf("=============================================\n");
	return 0;
}

int load_interface_file(struct INTERFACE_HEAD* ih){
	if(strcmp(ih->osType,"ubuntu") == 0){
		FILE* fp = fopen("/etc/network/interfaces","r");
		
		char buf[256] = {0};
		int bufLen = 0;

		int isComplete = 0;
		
		struct INTERFACE_NODE* in = NULL;

		while(fgets(buf,sizeof(buf),fp) != NULL){
			// delete '\n'
			buf[strlen(buf)-1] = 0;
			// omitted '#' '//'
			if(buf[0] == '#' || buf[0] == '\n' || buf[0] == '/' || buf[0] == '\0'){
				printf("this line '%s' will be omitted\n",buf);
				continue;			
			}

			//==================================================================
			char *line = buf;
			char* tmp;
			char *arr[10];
			for(int i = 0; (arr[i] = strtok_r(line," ",&tmp))!=NULL && i<10; ++i,line=NULL);
			
	
			// ----------------- auto ------------------
			if(strstr(arr[0],"auto") != NULL){
				if(in != NULL){
					struct INTERFACE_NODE* tmp = in;
					add_interface_node(ih,tmp);
				}
	
				in = create_interface_node();
				strcpy(in->name,arr[1]);
						
			}
			// ----------------- iface ------------------
			if(strstr(arr[0],"iface") != NULL){
				if(strcmp(arr[1],in->name) != 0){
					printf("in.name=%s, line name =%s,error file\n",in->name,arr[1]);
				}
				strcpy(in->mode,arr[3]);
			}

			// ----------------- address ----------------
			if(strstr(arr[0],"address") != NULL){
				strcpy(in->address,arr[1]);
			}

			// ----------------- netmask ----------------
			if(strstr(arr[0],"netmask") != NULL){
				strcpy(in->netmask,arr[1]);
			}
			// ----------------- gateway ----------------
			if(strstr(arr[0],"gateway") != NULL){
				strcpy(in->gateway,arr[1]);
			}
			//==================================================================
			bzero(buf,sizeof(buf));
		}
		fclose(fp);
		if(in!=NULL){
			struct INTERFACE_NODE* tmp = in;
			add_interface_node(ih,tmp);	
		}
	}
}

struct INTERFACE_NODE* find_interface_node(struct INTERFACE_HEAD* ih,char* name){
    struct INTERFACE_NODE *p = ih->fin;
    struct INTERFACE_NODE *q;
    if (p == NULL) {
	return NULL;
    }
    if (strcmp(p->name,"name") == 0) {
        return p;
    }
    while (p->next) {
        if (strcmp(p->next->name,"name") == 0) {
		return p->next;
        }
        p = p->next;
    }
    return NULL;
}

int write_interface_conf(struct INTERFACE_HEAD* ih){
	struct INTERFACE_NODE* p = ih->fin;
	if(strcmp(ih->osType,"ubuntu") == 0){
		char block[1024] = {0};
		int offset = 0;
		while(p){
			if(strlen(p->name)>0){
				offset += snprintf(block+offset,sizeof block - offset,"auto %s\n",p->name);
			}
			if(strlen(p->mode)>0){
				offset += snprintf(block+offset,sizeof block - offset,"\tiface %s inet %s\n",p->name,p->mode);
			}
			if(strlen(p->address)>0){
				offset += snprintf(block+offset,sizeof block - offset,"\taddress %s\n",p->address);
			}
			if(strlen(p->netmask)>0){
				offset += snprintf(block+offset,sizeof block - offset,"\tnetmask %s\n",p->netmask);
			}
			if(strlen(p->gateway)>0){
				offset += snprintf(block+offset,sizeof block - offset,"\tgateway %s\n",p->gateway);
			}
			p = p->next;
		}

		printf("=============================================\n");
		printf("block =\n%s\n",block);
		printf("=============================================\n");

		FILE* fp = fopen("/etc/network/interface","w");
		fwrite(block,sizeof(block),1,fp);
		fclose(fp);
	}
	return 0;

}

int modify_local_ip(struct INTERFACE_HEAD* ih,char* name, char* mode, char* address, char* netmask, char* gateway){
	struct INTERFACE_NODE *in = find_interface_node(ih,name);
	if (in == NULL){
		//add new 
		in = create_interface_node();
		strcpy(in->name,name);
		strcpy(in->mode,mode);
		strcpy(in->address,address);
		strcpy(in->netmask,netmask);
		if(strlen(gateway)>0){
			strcpy(in->gateway,gateway);
		}
		add_interface_node(ih,in);
		//add new to conf
	}else{
		strcpy(in->name,name);
		strcpy(in->mode,mode);
		strcpy(in->address,address);
		strcpy(in->netmask,netmask);
		if(strlen(gateway)>0){
			strcpy(in->gateway,gateway);
		}
	}

	write_interface_conf(ih);
	return 0;
}

int main(){
	char name[32] = "ens34";
	char mode[32] = "static";
	char address[32] = "192.168.1.1";
	char netmask[32] = "255.255.255.0";
	char gateway[32] = "";

	struct INTERFACE_HEAD* ih = create_interface_head("ubuntu");

	load_interface_file(ih);

	printf("%d\n",ih->num);
	traverse_interface(ih);
	modify_local_ip(ih,name,mode,address,netmask,gateway);
	traverse_interface(ih);
	return 0;
}