65 lines
1.4 KiB
C
65 lines
1.4 KiB
C
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#include <stdio.h>
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#include <string.h>
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#define ESCAPE_SEQS \
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X('\a', 'a') X('\b', 'b') X('\f', 'f') X('\n', 'n') \
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X('\r', 'r') X('\t', 't') X('\v', 'v')
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#define SIZE 1000
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void escape(char *s, char *t);
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void unescape(char *s, char *t);
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/* runs escape and unescape on stdin, prints results*/
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int main()
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{
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int i, c;
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char s[SIZE+1], t[2*SIZE+1];
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for (i = 0; (c = getchar()) != EOF; i++) {
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if (i >= SIZE) {
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printf("warning : buffer overflow\n");
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break;
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}
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s[i] = c;
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}
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s[i] = '\0';
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escape(s, t);
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printf("--- escaped ---\n%s\n", t);
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unescape(t, s);
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printf("\n-- unescaped --\n%s", s);
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return 0;
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}
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/* escape: makes escape sequences visible as it copies s to t
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* size of t must be 2*size of s */
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void escape(char *s, char *t)
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{
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for (; *s != '\0'; s++, t++)
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switch (*s) {
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#define X(e, c) case e : *(t++) = '\\'; *t = c; break;
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ESCAPE_SEQS
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#undef X
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default : *t = *s; break;
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}
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*t = '\0';
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}
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/* unescape: inverse of escape */
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void unescape(char *s, char *t)
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{
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for (; *s != '\0'; s++, t++) {
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if (*s == '\\')
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switch (*(s+1)) {
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#define X(e, c) case c : *t = e; s++; continue;
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ESCAPE_SEQS
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#undef X
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}
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*t = *s;
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}
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*t = '\0';
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}
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