使用不同的子进程在C中编写WC模拟器
这是我到目前为止为wc linux命令的模拟器得到的最终结果。 我必须完成这样的输出
This is child process 0, the number of lines is x This is child process 1, the number of words is y This is child process 2, the number of lines is z
我写的代码是这样的：
#include #include #include #include #include #include char* concat(char *s1, char *s2) { char *result = malloc(strlen(s1)+strlen(s2)+1); strcpy(result, s1); strcat(result, s2); return result; } int countLines(FILE *f){ int count = 0; char ch; while ((ch = fgetc(f)) != EOF){ if (ch == '\n') count++; } return count; } int countWords(FILE *f){ int countW = 0; char ch; while ((ch = fgetc(f)) != EOF){ if (ch == ' ') countW++; } return countW; } int countChars(FILE *f){ int chars = 0; char ch; while ((ch = fgetc(f)) != EOF){ chars++; } return chars; } int main(int argc, char** argv) { int lineCount = 0; int wordCount = 0; int charCount = 0; int n = 3; int i,status; int pids[3]; char *theprogram = argv[0]; char *thefile = argv[1]; if ( argc !=2 ) { printf( "Help: %s filename\n", argv[0]); } else{ FILE *file = fopen( argv[1], "r"); if(file == 0){ char *sub = concat(theprogram, ": "); char *middle = concat(sub, thefile); perror(middle); } else{ for (i = 0; i < n; i++) { pids[i] = fork(); if ( pids[i] < 0) { perror("fork"); exit(-1); } else if (pids[i] == 0) { if (i==0){ lineCount += countLines(file); printf("This is child proccess %d, and the number of lines is %d\n", i+1, lineCount); exit(0); } else if (i==1){ wordCount += countWords(file); printf("This is child proccess %d, and the number of words is %d\n", i+1, wordCount); exit(0); } else { charCount += countChars(file); printf("This is child proccess %d, and the number of characters is %d\n", i+1, charCount); exit(0); } } } return 0; } } }
这是我得到的实际输出：
% ./a.out mywc.c This is child proccess 2, and the number of words is 0 This is child proccess 1, and the number of lines is 64 This is child proccess 3, and the number of characters is 0 This is child proccess 3, and the number of characters is 0 This is child proccess 2, and the number of words is 0 This is child proccess 3, and the number of characters is 0 This is child proccess 3, and the number of characters is 0
我在做什么错了？ 我是C编程的新手，所以不确定我错过了什么。
谢谢。
编辑
退出退出代码，但现在无法获得字数和字符数。
我的问题的正确代码在这里：
#include #include #include #include #include #include char* concat(char *s1, char *s2) { char *result = malloc(strlen(s1)+strlen(s2)+1); strcpy(result, s1); strcat(result, s2); return result; } int countLines(char *f){ FILE *file = fopen(f, "r"); int count = 0; char ch; while ((ch = fgetc(file)) != EOF){ if (ch == '\n') count++; } return count; } int countWords(char *f){ char buffer[1]; FILE *file = fopen(f, "r"); int countW = 0; enum states { WSP, WRD }; int state = WSP; char last = ' '; while (read(fileno(file),buffer,1) == 1 ) { if ( buffer[0]== ' ' || buffer[0] == '\t' || buffer[0]=='\n' ) { state = WSP; } else { if ( state == WSP ) { countW++; } state = WRD; } last = buffer[0]; } return countW; } int countChars(char *f){ FILE *file = fopen(f, "r"); int chars = 0; char ch; while ((ch = fgetc(file))){ if (ch == EOF) break; chars++; } return chars; } int main(int argc, char** argv) { int lineCount = 0; int wordCount = 0; int charCount = 0; int n = 3; int i,status; int pids[3]; char *theprogram = argv[0]; char *thefile = argv[1]; if ( argc !=2 ) { printf( "Help: %s filename\n", argv[0]); } else{ FILE *file = fopen( argv[1], "r"); if(file == 0){ char *sub = concat(theprogram, ": "); char *middle = concat(sub, thefile); perror(middle); } else{ for (i = 0; i < n; i++) { pids[i] = fork(); if ( pids[i] < 0) { perror("fork"); exit(-1); } else if (pids[i] == 0) { if (i==0){ lineCount = countLines(argv[1]); printf("This is child proccess %d, and the number of lines is %d\n", i+1, lineCount); exit(0); } else if (i==1){ wordCount = countWords(argv[1]); printf("This is child proccess %d, and the number of words is %d\n", i+1, wordCount); exit(0); } else { charCount += countChars(argv[1]); printf("This is child proccess %d, and the number of characters is %d\n", i+1, charCount); exit(0); } } } return 0; } } }