- Fix --color behaviour to only output color sequences if stdout is a tty

or if forced mode is specified [1]
- While here, add some alternative names for the options and make then
  case-insensitive
- Fix -q and -l behaviour [2]
- Some small changes to make the code easier to review

Submitted by:   swell.k@gmail.com [1],
                dougb [2]
Approved by:    delphij (mentor)

usr.bin/grep/grep.c

@@ -114,13 +114,13 @@ bool	 lbflag;	/* --line-buffered */
 bool	 nullflag;	/* --null */
 bool	 exclflag;	/* --exclude */
 char	*label;		/* --label */
-char	*color;		/* --color */
+const char *color;	/* --color */
 int	 grepbehave = GREP_BASIC;	/* -EFGP: type of the regex */
 int	 binbehave = BINFILE_BIN;	/* -aIU: handling of binary files */
 int	 filebehave = FILE_STDIO;	/* -JZ: normal, gzip or bzip2 file */
-int	 devbehave = DEV_GREP;		/* -D: handling of devices */
-int	 dirbehave = DIR_GREP;		/* -dRr: handling of directories */
-int	 linkbehave = LINK_GREP;	/* -OpS: handling of symlinks */
+int	 devbehave = DEV_READ;		/* -D: handling of devices */
+int	 dirbehave = DIR_READ;		/* -dRr: handling of directories */
+int	 linkbehave = LINK_READ;	/* -OpS: handling of symlinks */
 
 enum {
 	BIN_OPT = CHAR_MAX + 1,
@@ -136,6 +136,8 @@ enum {
 	R_DINCLUDE_OPT
 };
 
+static inline const char	*init_color(const char *);
+
 /* Housekeeping */
 bool	 first = true;	/* flag whether we are processing the first match */
 bool	 prev;		/* flag whether or not the previous line matched */
@@ -279,6 +281,15 @@ read_patterns(const char *fn)
 	fclose(f);
 }
 
+static inline const char *
+init_color(const char *d)
+{
+	char *c;
+
+	c = getenv("GREP_COLOR");
+	return (c != NULL ? c : d);
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -415,16 +426,24 @@ main(int argc, char *argv[])
 			cflag = true;
 			break;
 		case 'D':
-			if (strcmp(optarg, "skip") == 0)
+			if (strcasecmp(optarg, "skip") == 0)
 				devbehave = DEV_SKIP;
+			else if (strcasecmp(optarg, "read") == 0)
+				devbehave = DEV_READ;
+			else {
+				errno = EINVAL;
+				err(2, NULL);
+			}
 			break;
 		case 'd':
-			if (strcmp("recurse", optarg) == 0) {
+			if (strcasecmp("recurse", optarg) == 0) {
 				Hflag = true;
 				dirbehave = DIR_RECURSE;
-			} else if (strcmp("skip", optarg) == 0)
+			} else if (strcasecmp("skip", optarg) == 0)
 				dirbehave = DIR_SKIP;
-			else if (strcmp("read", optarg) != 0) {
+			else if (strcasecmp("read", optarg) == 0)
+				dirbehave = DIR_READ;
+			else {
 				errno = EINVAL;
 				err(2, NULL);
 			}
@@ -466,11 +485,11 @@ main(int argc, char *argv[])
 			break;
 		case 'L':
 			lflag = false;
-			Lflag = qflag = true;
+			Lflag = true;
 			break;
 		case 'l':
 			Lflag = false;
-			lflag = qflag = true;
+			lflag = true;
 			break;
 		case 'm':
 			mflag = true;
@@ -500,7 +519,7 @@ main(int argc, char *argv[])
 			qflag = true;
 			break;
 		case 'S':
-			linkbehave = LINK_GREP;
+			linkbehave = LINK_READ;
 			break;
 		case 'R':
 		case 'r':
@@ -533,26 +552,33 @@ main(int argc, char *argv[])
 			filebehave = FILE_GZIP;
 			break;
 		case BIN_OPT:
-			if (strcmp("binary", optarg) == 0)
+			if (strcasecmp("binary", optarg) == 0)
 				binbehave = BINFILE_BIN;
-			else if (strcmp("without-match", optarg) == 0)
+			else if (strcasecmp("without-match", optarg) == 0)
 				binbehave = BINFILE_SKIP;
-			else if (strcmp("text", optarg) == 0)
+			else if (strcasecmp("text", optarg) == 0)
 				binbehave = BINFILE_TEXT;
 			else
 				errx(2, "%s", getstr(8));
 			break;
 		case COLOR_OPT:
-			if (optarg == NULL || strcmp("auto", optarg) == 0 ||
-			    strcmp("always", optarg) == 0 ) {
-				color = getenv("GREP_COLOR");
-				if (color == NULL) {
-					color = grep_malloc(sizeof(char) * 6);
-					strcpy(color, "01;31");
-				}
-			} else if (strcmp("never", optarg) == 0)
-				color = NULL;
-			else
+			color = NULL;
+			if (optarg == NULL || strcasecmp("auto", optarg) == 0 ||
+			    strcasecmp("tty", optarg) == 0 ||
+			    strcasecmp("if-tty", optarg) == 0) {
+				char *term;
+
+				term = getenv("TERM");
+				if (isatty(STDOUT_FILENO) && term != NULL &&
+				    strcasecmp(term, "dumb") != 0)
+					color = init_color("01;31");
+			} else if (strcasecmp("always", optarg) == 0 ||
+			    strcasecmp("yes", optarg) == 0 ||
+			    strcasecmp("force", optarg) == 0) {
+				color = init_color("01;31");
+			} else if (strcasecmp("never", optarg) != 0 &&
+			    strcasecmp("none", optarg) != 0 &&
+			    strcasecmp("no", optarg) != 0)
 				errx(2, "%s", getstr(3));
 			break;
 		case LABEL_OPT:

usr.bin/grep/grep.h

@@ -60,14 +60,14 @@ extern const char		*errstr[];
 #define FILE_GZIP	1
 #define FILE_BZIP	2
 
-#define DIR_GREP	0
+#define DIR_READ	0
 #define DIR_SKIP	1
 #define DIR_RECURSE	2
 
-#define DEV_GREP	0
+#define DEV_READ	0
 #define DEV_SKIP	1
 
-#define LINK_GREP	0
+#define LINK_READ	0
 #define LINK_EXPLICIT	1
 #define LINK_SKIP	2
 
@@ -120,7 +120,8 @@ extern bool	 Eflag, Fflag, Gflag, Hflag, Lflag,
 		 qflag, sflag, vflag, wflag, xflag;
 extern bool	 exclflag, nullflag;
 extern unsigned long long Aflag, Bflag, mcount;
-extern char	*color, *label;
+extern char	*label;
+extern const char *color;
 extern int	 binbehave, devbehave, dirbehave, filebehave, grepbehave, linkbehave;
 
 extern bool	 first, matchall, notfound, prev;

usr.bin/grep/util.c

@@ -226,9 +226,9 @@ procfile(const char *fn)
 			printf("%s:", ln.file);
 		printf("%u\n", c);
 	}
-	if (lflag && c != 0)
+	if (lflag && !qflag && c != 0)
 		printf("%s\n", fn);
-	if (Lflag && c == 0)
+	if (Lflag && !qflag && c == 0)
 		printf("%s\n", fn);
 	if (c && !cflag && !lflag && !Lflag &&
 	    binbehave == BINFILE_BIN && f->binary && !qflag)
@@ -320,7 +320,8 @@ procline(struct str *l, int nottext)
 					if (m < MAX_LINE_MATCHES)
 						matches[m++] = pmatch;
 					/* matches - skip further patterns */
-					break;
+					if ((color != NULL && !oflag) || qflag || lflag)
+						break;
 				}
 			}
 
@@ -329,7 +330,7 @@ procline(struct str *l, int nottext)
 				break;
 			}
 			/* One pass if we are not recording matches */
-			if (!oflag && !color)
+			if ((color != NULL && !oflag) || qflag || lflag)
 				break;
 
 			if (st == (size_t)pmatch.rm_so)