[hackers] [sbase] Rewrite foldline() in fold(1) || FRIGN

From: <git_AT_suckless.org>
Date: Tue, 24 Mar 2015 23:54:16 +0100 (CET)

commit fbda47b96470c2c9278cf4902fb517a2882137b4
Author: FRIGN <dev_AT_frign.de>
Date: Mon Mar 16 19:26:42 2015 +0100

    Rewrite foldline() in fold(1)
    
    After the audit, I had this noted down as a TODO-item, but
    considered the function to be tested enough to hold the line
    until I came to rewrite it.
    Admittedly, I didn't take a closer look at the previous loop
    and there probably were some edge-cases which caused trouble, but
    so far so good, the new version of this commit should be safe
    and considered audited.

diff --git a/fold.c b/fold.c
index 020d429..c176497 100644
--- a/fold.c
+++ b/fold.c
_AT_@ -3,6 +3,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "util.h"
 
_AT_@ -11,46 +12,41 @@ static int sflag = 0;
 static size_t width = 80;
 
 static void
-foldline(const char *str)
-{
- size_t i = 0, n = 0, col, j;
- int space;
- char c;
-
- do {
- space = 0;
- for (j = i, col = 0; str[j] && col <= width; j++) {
- c = str[j];
- if (!UTF8_POINT(c) && !bflag)
- continue;
- if (sflag && isspace(c)) {
- space = 1;
- n = j + 1;
- } else if (!space) {
- n = j;
- }
+foldline(const char *str) {
+ const char *p, *spacesect = NULL;
+ size_t col, off;
 
- if (!bflag && iscntrl(c)) {
- switch(c) {
- case '\b':
- col--;
- break;
- case '\r':
- col = 0;
- break;
- case '\t':
- col += (col + 1) % 8;
- break;
- }
- } else {
- col++;
+ for (p = str, col = 0; *p && *p != '\n'; p++) {
+ if (!UTF8_POINT(*p) && !bflag)
+ continue;
+ if (col >= width) {
+ off = (sflag && spacesect) ? spacesect - str : p - str;
+ if (fwrite(str, 1, off, stdout) != off)
+ eprintf("fwrite <stdout>:");
+ putchar('\n');
+ spacesect = NULL;
+ col = 0;
+ p = str += off;
+ }
+ if (sflag && isspace(*p))
+ spacesect = p + 1;
+ if (!bflag && iscntrl(*p)) {
+ switch(*p) {
+ case '\b':
+ col -= (col > 0);
+ break;
+ case '\r':
+ col = 0;
+ break;
+ case '\t':
+ col += (col + 1) % 8;
+ break;
                         }
+ } else {
+ col++;
                 }
- if (fwrite(str + i, 1, n - i, stdout) != n - i)
- eprintf("fwrite <stdout>:");
- if (str[n])
- putchar('\n');
- } while (str[i = n] && str[i] != '\n');
+ }
+ fputs(str, stdout);
 }
 
 static void
_AT_@ -69,7 +65,7 @@ fold(FILE *fp, const char *fname)
 static void
 usage(void)
 {
- eprintf("usage: %s [-bs] [-w width | -width] [FILE...]\n", argv0);
+ eprintf("usage: %s [-bs] [-w num | -num] [FILE ...]\n", argv0);
 }
 
 int
_AT_@ -102,10 +98,10 @@ main(int argc, char *argv[])
                         if (!(fp = fopen(*argv, "r"))) {
                                 weprintf("fopen %s:", *argv);
                                 ret = 1;
- continue;
+ } else {
+ fold(fp, *argv);
+ fclose(fp);
                         }
- fold(fp, *argv);
- fclose(fp);
                 }
         }
 
Received on Tue Mar 24 2015 - 23:54:16 CET