因为我还是编程新手，所以请耐心等待。我需要阅读/proc/cpuinfo来确定路由器的模型，文件如下所示：
system type : bcm63xx/HW553 (0x6358/0xA1)
machine : Unknown
processor : 0
cpu model : Broadcom BMIPS4350 V1.0
BogoMIPS : 299.26
wait instruction : yes
microsecond timers : yes
tlb_entries : 32
extra interrupt vector : yes
hardware watchpoint : no
isa : mips1 mips2 mips32r1
ASEs implemented :
shadow register sets : 1
kscratch registers : 0
core : 0
VCED exceptions : not available
VCEI exceptions : not available
我需要在变量中存储的是此部分bcm63xx/HW553 (0x6358/0xA1)。这是型号，它不断变化，这是我迄今为止所尝试的：
#include <stdio.h>
int main ( void )
{
char filename[] = "/proc/cpuinfo";
FILE *file = fopen ( filename, "r" );
if (file != NULL) {
char line [1000];
while(fgets(line,sizeof line,file)!= NULL) /* read a line from a file */ {
fprintf(stdout,"%s",line); //print the file contents on stdout.
}
fclose(file);
}
else {
perror(filename); //print the error message on stderr.
}
return 0;
}
但是该脚本只打印文件，我不知道如何将路由器的模型存储在变量中，我应该怎么做？
PS： 将路由器的模型存储在变量中后，我需要比较它是否与预定义的变量匹配。
更新
我试图让它成为一个函数，我的代码是：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char* model() {
char filename[] = "/proc/cpuinfo";
char* key = "system type";
char* value;
FILE *file = fopen(filename, "r");
if (file != NULL) {
char line[1000];
char* router_model = NULL;
while (fgets(line, sizeof line, file) != NULL) /* read a line from a file */ {
fprintf(stdout, "%s", line); //print the file contents on stdout.
if (strncmp(line, key, strlen(key)) == 0) {
char* value = strchr(line, ':');
value += 2;
router_model = strdup(value);
break; // once the key has been found we can stop reading
}
}
fclose(file);
if (router_model != NULL) {
printf("The model is %s\n", router_model); // print router model
}
else {
printf("No %s entry in %s\n", key, filename); // key not found, print some error message
}
free(router_model);
}
else {
perror(filename); //print the error message on stderr.
}
return router_model;
}
int main(void)
{
char* ret;
ret = model();
printf("Model: %s\n", ret);
return 0;
}
但是我收到了一个错误：
test.c: In function ‘model’:
test.c:37:9: error: ‘router_model’ undeclared (first use in this function)
return router_model;
^~~~~~~~~~~~
test.c:37:9: note: each undeclared identifier is reported only once for each function it appears in
我该如何解决？
答案 0 :(得分：1)
获得行后，请检查它是否以您要查找的密钥字符串开头。
char* key = "system type";
...
if (strncmp(line, key, strlen(key)) == 0) {
/* this is the line you want */
}
一旦确定了该行，找到第一个冒号。
char* value = strchr(line, ':');
现在你有了这个值，虽然它会包含前导冒号和空格，所以你可以迭代它们。
value += 2;
然后你应该能够使用这个结果。请注意，我没有分配任何新空间。如果要在某处保存此值，则需要复制字符串。最简单的方法是复制。
char* router_model = strdup(value);
完成后，您必须free()此字符串。
答案 1 :(得分：0)
你想要这个：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
char filename[] = "/proc/cpuinfo";
char* key = "system type";
char* value;
FILE *file = fopen(filename, "r");
if (file != NULL) {
char line[1000];
char* router_model = NULL;
while (fgets(line, sizeof line, file) != NULL) /* read a line from a file */ {
fprintf(stdout, "%s", line); //print the file contents on stdout.
if (strncmp(line, key, strlen(key)) == 0) {
char* value = strchr(line, ':');
value += 2;
router_model = strdup(value);
break; // once the key has been found wen can stop reading
}
}
fclose(file);
if (router_model != NULL)
printf("The model is %s\n", router_model); // print router model
else
printf("No %s entry in %s\n", key, filename); // key not found, print some error message
free(router_model);
}
else {
perror(filename); //print the error message on stderr.
}
return 0;
}
这是您的代码，略有修改和一些注释。
请注意，仍有改进的余地。
答案 2 :(得分：0)
使用strtok和strip，修剪以实现上述程序的键值对。这样就可以轻松比较关键和明确的问题逻辑。
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
char *strip(char *str){
if(str == NULL){
return str;
}
int j = 0;
while(str[0] != '\0' && isspace(str[0])){
j=0;
while(str[j] != '\0'){
str[j] = str[j+1];
j++;
}
}
return str;
}
char *trim(char *str){
if(str == NULL){
return str;
}
int len = strlen(str)-1;
while(isspace(str[len])){
str[len]='\0';
len--;
}
return str;
}
int process_line(char *str, char *res_key, char *res_value){
char *key, *value;
key = strtok(str, ":");
value = strtok(NULL, ":");
if( key && value){
key = strip(key);
key = trim(key);
value = strip(value);
value = trim(value);
//printf("%s:%s\n", key, value);
strcpy(res_key, key);
strcpy(res_value, value);
}
}
int main(int argc, char *argv[])
{
char filename[] = "/proc/cpuinfo";
char* key = "system type";
char* value;
FILE *file = fopen(filename, "r");
if (file != NULL) {
char line[2048]={0x00};
char temp_key[1024]={0x00};
char temp_value[1024]={0x00};
while (fscanf(file, " %[^\n]s", line) != EOF) /* read a line from a file */ {
process_line(line, temp_key, temp_value);
if(strcmp(temp_key, key) == 0){
break;
}
memset(line, 0x00, sizeof(line));
memset(temp_key, 0x00, sizeof(temp_key));
memset(temp_value, 0x00, sizeof(temp_value));
}
fclose(file);
printf("model:%s\n", temp_value);
}
else {
perror(filename);
}
return 0;
}
我认为这应该可以解决你的问题