TCU

A reimplementation of the BSD core utilities written in C.
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head.c (1889B)

      1 /* Terrible implementation of the head core util */
      2 /* For license infomration see the LICENSE file included in this repo */
      3 #include<stdio.h>
      4 #include<stdlib.h>
      5 #include<string.h>
      6 
      7 int main(int argc, char *argv[]) {
      8   FILE *fp;
      9   char ch;
     10   int lines = 10; // Default number of lines, can be chaged at runtime with -n arg
     11   int i = 0;
     12   int files = 1;
     13   int delimeter = 0;
     14 
     15   int argByte = strcmp(argv[1], "-c");
     16   if (argByte == 0) {
     17     int bytes = strtol(argv[2], NULL, 10);
     18     files = 3;
     19     if (files == (argc - 1)) {
     20       fp = fopen(argv[files], "r");
     21       i = 0;
     22       while(((ch = fgetc(fp)) != EOF) && (i < bytes)) {
     23         printf("%c", ch);
     24         i++;
     25       }
     26       return 0;
     27     } else {
     28         for (files = files; files < argc; files++) {
     29         fp = fopen(argv[files], "r");
     30         i = 0;
     31         printf("==> %s <==\n", argv[files]);
     32         while(((ch = fgetc(fp)) != EOF) && (i < bytes)) {
     33           printf("%c", ch);
     34           i++;
     35         }
     36         fclose(fp);
     37       }
     38         return 0;
     39      }
     40   }
     41 
     42   int argLine = strcmp(argv[1], "-n");
     43   if (argLine == 0) {
     44     lines = strtol(argv[2], NULL, 10);
     45     files = 3;
     46   }
     47 
     48   if (files == (argc - 1)) {
     49     fp = fopen(argv[files], "r");
     50     while((ch = fgetc(fp)) != EOF) {
     51       if (i >= lines) {
     52         fclose(fp);
     53         i = 0;
     54         break;
     55       } else if (ch == '\n') {
     56         printf("%c", ch);
     57         i++;
     58       } else {
     59         printf("%c", ch);
     60       }
     61     }
     62     return 0;
     63   }
     64     for (files = files; files < argc; files++) {
     65       fp = fopen(argv[files], "r");
     66       printf("==> %s <==\n", argv[files]);
     67       while((ch = fgetc(fp)) != EOF) {
     68         if (i >= lines) {
     69           fclose(fp);
     70           i = 0;
     71           break;
     72         } else if (ch == '\n') {
     73           printf("%c", ch);
     74           i++;
     75         } else {
     76           printf("%c", ch);
     77         }
     78       }
     79       fclose(fp);
     80     }
     81   return 0;
     82 }