48 lines
1.2 KiB
C
48 lines
1.2 KiB
C
#include <stdio.h>
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#include <unistd.h>
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int wc(FILE* fp)
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{
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char c[1];
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int seen_word = 0, seen_sep_after_word = 0, num_words = 0;
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int fn = fileno(fp);
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while (read(fn, c, sizeof(c)) > 0) {
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if (*c == '\n' || *c == ' ' || *c == '\t') {
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if (seen_word) {
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seen_sep_after_word = 1;
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}
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} else {
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seen_word = 1;
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}
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// exercise: what happens if you only track seen_sep,
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// instead of seen_sep_after_word?
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// test with: $ echo " hello world" | ./wc
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if (seen_word && seen_sep_after_word) {
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num_words++;
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seen_sep_after_word = seen_word = 0;
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}
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}
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num_words+=seen_word;
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printf("%i\n", num_words);
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return 0;
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}
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int main(int argc, char** argv)
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{
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if (argc == 1) {
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return wc(stdin);
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} else if (argc > 1) {
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FILE* fp = fopen(argv[1], "r");
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if (!fp) {
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perror("Could not open file");
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return 1;
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}
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return wc(fp) && fclose(fp);
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} else {
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printf("Usage: ww file.txt\n");
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printf(" or: cat file.txt | ww\n");
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printf(" or: ww # read from user-inputted stdin\n");
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}
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return 0;
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}
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