diff options
Diffstat (limited to 'reference/C/CONTRIB/SNIP/c_cmnt.c')
| -rwxr-xr-x | reference/C/CONTRIB/SNIP/c_cmnt.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/reference/C/CONTRIB/SNIP/c_cmnt.c b/reference/C/CONTRIB/SNIP/c_cmnt.c new file mode 100755 index 0000000..d2df7c3 --- /dev/null +++ b/reference/C/CONTRIB/SNIP/c_cmnt.c @@ -0,0 +1,154 @@ +/* Extract comments from a C program source file.
+**
+** This program acts as a filter to copy comments in a C source
+** file to the output. Each comment includes the starting and
+** ending delimiters and is followed by a newline.
+**
+** Three #ifdef options are defined:
+** INHIBIT_TRIGRAPHS prevents recognition of trigraphs, which
+** can affect detection of escaped characters,
+** i.e., ??/" is an escaped quote.
+** TRANSLATE_TRIGRAPHS causes the output to have trigraphs
+** converted to the normal C characters.
+** CPP_MODE causes "//" to start a comment.
+** The default for these symbols is undefined, resulting in
+** operation on strict ANSI source, except as noted below.
+**
+** What makes this program interesting is that comment detection
+** should be inhibited within strings and character constants.
+**
+** Note: The name of a header following #include can, under ANSI,
+** contain any sequence of characters, except \n and the closing
+** > or ". This program doesn't inhibit comment, string, or character
+** constant detection within the header name, as an ANSI parser must.
+**
+** Written by and contributed to the public domain by
+** Thad Smith III, Boulder, CO, October 1990.
+*/
+
+#include <stdio.h>
+
+#ifndef INHIBIT_TRIGRAPHS /* default: recognize trigraphs */
+ #define getnc() getnsc(1) /* get char with trigraph xlate */
+ #ifdef TRANSLATE_TRIGRAPHS
+ #define getcmtc() getnsc(1) /* get comment char w/ t.g. xlate */
+ #else
+ #define getcmtc() getnsc(0) /* default: no comment t.g. xlate */
+ #endif
+
+/*
+** get next source character or EOF
+*/
+
+int getnsc(int cvtg) /* boolean: convert trigraphs */
+{
+ static int c, nc, nnc; /* next 3 characters */
+
+ /* shift in next source character */
+
+ c = nc; nc = nnc; nnc = getchar();
+
+ /* perform trigraph substitution */
+
+ if (cvtg && c == '?' && nc == '?')
+ {
+ switch (nnc)
+ {
+ case '=' :
+ c = '#' ;
+ break;
+ case '(' :
+ c = '[' ;
+ break;
+ case '/' :
+ c = '\\';
+ break;
+ case ')' :
+ c = ']' ;
+ break;
+ case '\'':
+ c = '^' ;
+ break;
+ case '<' :
+ c = '{' ;
+ break;
+ case '!' :
+ c = '|' ;
+ break;
+ case '>' :
+ c = '}' ;
+ break;
+ case '-' :
+ c = '~' ;
+ break;
+ default :
+ return c; /* no substitution */
+ }
+ nc = getchar(); nnc = getchar();
+ }
+ return c;
+}
+
+#else /* don't process trigraphs */
+
+ #define getnc() getchar()
+ #define getcmtc() getchar()
+#endif
+
+int main(void)
+{
+ int pc; /* previous character */
+ int c; /* current input character */
+
+#ifndef INHIBIT_TRIGRAPHS
+ getnc(); /* prime the pump */
+ getnc();
+#endif
+ c = getnc(); /* get first char */
+
+ for (;;) /* in non-comment area */
+ {
+ switch (c)
+ {
+ case '/': /* possible start of comment */
+ if ((c= getnc()) == '*') /* process comment */
+ {
+ putchar('/');
+ putchar('*');
+
+ /* copy comment to stdout */
+
+ for (pc = 0; (c = getcmtc()) != EOF &&
+ (putchar(c) != '/' || pc != '*'); pc=c)
+ ;
+ putchar('\n');
+#ifdef CPP_MODE
+ }
+ else if (c == '/') /* '//' comment */
+ {
+ putchar('/');
+ putchar('/');
+ while ((c = getcmtc()) != EOF && putchar(c) != '\n')
+ ;
+#endif
+ }
+ else continue; /* test current char */
+ break;
+
+ case '\"': /* start of string */
+ case '\'': /* start of (possibly multi-byte) char constant */
+ pc = c; /* save delimiter */
+ do /* scan through character constant,
+ ** discarding escape chars
+ */
+ {
+ while ((c = getnc()) == '\\')
+ getnc();
+ } while (c != pc && c != EOF);
+ break;
+ }
+ if (c == EOF)
+ return 0;
+ else c = getnc();
+ }
+}
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