如何在c语言的文本输入文件中找到匹配括号或大括号的位置?
我正在用C.编写一个程序,它打开一个包含类似C的源代码的纯文本文件,读取该文件,并输出一个与第一个文件内容相同的文件,只是删除了所有注释。程序必须检查所有括号是否匹配,如果不匹配,程序应显示错误消息,在显示错误类型和遇到此错误的行号时。我显示了一条错误消息,但如何找到错误位置。。?输入和输出文件被传递到程序和行参数,如下所示: ./u可执行文件inputfile.txt outputfile.txt 以下是我编写的代码:如何在c语言的文本输入文件中找到匹配括号或大括号的位置?,c,C,我正在用C.编写一个程序,它打开一个包含类似C的源代码的纯文本文件,读取该文件,并输出一个与第一个文件内容相同的文件,只是删除了所有注释。程序必须检查所有括号是否匹配,如果不匹配,程序应显示错误消息,在显示错误类型和遇到此错误的行号时。我显示了一条错误消息,但如何找到错误位置。。?输入和输出文件被传递到程序和行参数,如下所示: ./u可执行文件inputfile.txt outputfile.txt 以下是我编写的代码: #include <stdio.h> #include <
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/* Functions */
void check_comment (char) ; // checks for both types of comments, then passes on control to below comments
void block_comment () ; // handles block or multiline comments
void single_comment () ; // handles single line comments
/* 2 file pointers - 1st is for the file in which we check for comments,
and 2nd is the file in which we copy the code after removing comments */
FILE *fp , *fp2;
int main(void)
{
char c;
fp = fopen ("inputfile.txt","r") ; // open the first file in read mode
fp2 = fopen ("outputfile.txt","w") ; // open the second file in write mode
while((c=fgetc(fp))!=EOF) // read the file character by character
check_comment(c); // check for each character if it seems like the beginning of a comment
// close both the files at the end of the program
fclose(fp);
fclose(fp2);
FILE *fp;
char fname[20];
char brackets[20] = "{}[]()";
int bracketCounts[6] = {0};
char * found;
int i;
printf("Please enter the destination of the file: \n");
scanf("%s", fname);
if ((fp = fopen(fname, "r")) == NULL){
printf("Problem opening file!\n");
return 0x00;
}
printf("File opened correctly\n");
// counting various parentheses
while ((c = getc(fp)) != EOF){
found = strchr(brackets, c);
if (found != NULL) {
bracketCounts[found - brackets]++;
}
}
// dont't forget to close file after reading is done
fclose(fp);
// checking parentheses counters
for (i=0; i < 6; i+=2) {
if (bracketCounts[i] != bracketCounts[i+1]) {
printf("Unbalanced parentheses !\n");
return 0x00;
}
}
printf("All parentheses are OK!\n");
return 0;
}
// function that handles both types of comments
void check_comment(char c)
{
char d;
if( c == '/') // if the character starts with '/', it 'could' be a comment
{
if((d=fgetc(fp))=='*') // if the next character we read is '*', it is the beginning of multiblock comment
block_comment(); // pass control to function that handles multiblock comments
else if( d == '/') // else if the next character we read is '/', it is the beginning of single line comment
{
single_comment();// pass control to function that handles single line comment
}
else
{
// if both the cases fail, it is not a comment, so we add the character as it is in the new file.
fputc(c,fp2);
fputc(d,fp2);
}
}
// again, if all above fails, we add the character as it is in the new file.
else
fputc(c,fp2);
}
// function that handles block comments
void block_comment()
{
char d,e;
while((d=fgetc(fp))!=EOF) // the block comment has started, read the character by character
{
/* keep reading the characters and do nothing,
as they do not have to be copied into the new file (we are removing the comments)
*/
if(d=='*') // if the comment 'seems' like ending
{
e=fgetc(fp); // check if it actually ends (block comments end with '*/')
if(e=='/') // if the comment 'has' ended, return from the function
return;
}
}
}
// function that handles single line comments
void single_comment()
{
char d,e;
while((d=fgetc(fp))!=EOF) // the single line comment has started, read the character by character
{
/* keep reading the characters and do nothing,
as they do not have to be copied into the new file (we are removing the comments)
*/
if(d=='\n') // check if the comment ends (single comments end with '\n', or newline)
return; // if the comment 'has' ended, return from the function
}
}
您可以实现或使用堆栈数据结构,在读取输入文件时,如果您得到{,或[push on the stack and if you get},或]pop the stack,则在输入文件的末尾,堆栈应为空,然后获得适当的匹配,否则会发生不匹配 除此之外,您还可以保留行号或位置等 例:1 2点左右 3点多 按,第1行,然后按,第2行,当你弹出时,第2行 如此类推,在这种情况下,如果你没有第二次收盘,你可以说,第1行
没有结束。您到底想问我们什么?我们不是一个基础广泛的帮助服务:我们期望的问题相当狭窄。看,线路号?不。或者扫描缩进。运行编译器!systemgcc inputfile.txt;我的意思是,如果有不匹配的括号,有没有办法显示错误在哪里?为什么我们可以只使用整数计数器并递增或递减它?如果我们有{{…}我们如何确定前两个遗漏中的哪一个是它的一半呢?堆栈也只是一种递增的push和decrementpop,但与一个数组一起,可以在每次递增和递减时提取关于事物的信息,我们可以根据requirement@purec:{..}第一个案件显然结束了吗{是缺少的一个,如果我们像{1,{2当我们到达时}我们弹出{2}我们留下了一个{1`@Shivyaragati或第二个…实际上没有办法确定哪一个遗漏了最后一个。按照惯例,第一个通常被挑选出来报告。