refactor psops(1)

libpsargs/libpsargs.c

@@ -7,7 +7,7 @@
 #define SCMPFLAT(a, b) (*(a) != '\0' && *((a)+1) == '\0' && *(a) == (b))
 
 int
-check_arg(char **args, char l, char r){
+check_arg(char **args){
 	enum {
 		UNINITIALIZED = 0,
 		NORMAL = 1,
@@ -27,8 +27,10 @@ check_arg(char **args, char l, char r){
 			/* decrement s if on an rparen, increment if on lparen
 			 * increment terms if on an rparen */
 			if(args[0][1] == '\0'){
-				s += (args[0][0] == l) - (args[0][0] == r);
-				terms += (args[0][0] == r && s == NORMAL);
+				s += (args[0][0] == L_PAREN)
+					- (args[0][0] == R_PAREN);
+				terms +=
+					(args[0][0] == R_PAREN && s == NORMAL);
 			}
 			break;
 		}
@@ -38,7 +40,7 @@ check_arg(char **args, char l, char r){
 }
 
 char **
-corresponding_arg(char **arg, char l, char r){
+corresponding_arg(char **arg){
 	size_t p;
 
 	for(p = 1; p > 0;){
@@ -46,9 +48,9 @@ corresponding_arg(char **arg, char l, char r){
 		/* branching here potentially saves a comparison.
 		 * this seems like the most optimal way to do this,
 		 * maybe it isn't, i don't care too much */
-		if(SCMPFLAT(*arg, l))
+		if(SCMPFLAT(*arg, L_PAREN))
 			++p;
-		else if(SCMPFLAT(*arg, r))
+		else if(SCMPFLAT(*arg, R_PAREN))
 			--p;
 	}
 

libpsargs/libpsargs.h

@@ -1,17 +1,22 @@
-/* pscat(1) and pspipe(1) arguments are flanked by { '[', '\0' } and
- * { ']', '\0' }. Nesting is allowed to facilitate nesting of pscat(1) and
- * pspipe(1). This checks to make sure grouping symbols in args are balanced.
- * args is the argv that was passed to main, incremented. l is the left
- * grouping character (usually '[') and r is the right grouping character
- * (usually ']').
+#ifndef L_PAREN
+#	define L_PAREN '['
+#endif
+
+#ifndef R_PAREN
+#	define R_PAREN ']'
+#endif
+
+/* psops(1) arguments are flanked by { '[', '\0' } and { ']', '\0' }. Nesting
+ * is allowed to facilitate nesting of psops(1) programs. This checks to make
+ * sure grouping symbols in args are balanced.
+ * args is the argv that was passed to main, incremented (so args[1] is "[").
  * Returns 0 in the events of a syntax error or there being no arguments.
  * Otherwise, returns the number of top-level right grouping arguments
  * (i.e. the number of terms). */
-int check_arg(char **args, char l, char r);
+int check_arg(char **args);
 
 /* arg is the location of the argument with the left grouping symbol within
- * argv, l is the left grouping character itself, r is the right grouping
- * character itself.
+ * argv.
  * Returns the location of the argument with the corresponding left grouping
  * symbol within argv. */
-char **corresponding_arg(char **arg, char l, char r);
+char **corresponding_arg(char **arg);

pscat/Makefile

@@ -1,16 +1,18 @@
+CFLAGS += -g -I../libpsargs
+
 all: pscat
 
 pscat: pscat.o ../libpsargs/libpsargs.o
-	$(CC) $(CFLAGS) -g -o pscat ../libpsargs/libpsargs.o pscat.o
+	$(CC) $(CFLAGS) -o $@ pscat.o ../libpsargs/libpsargs.o
 
-pscat.o: pscat.c
-	$(CC) $(CFLAGS) -c -DPSCAT=1 -I../libpsargs -o pscat.o pscat.c
+pscat.o: pscat.c psops.c
+	$(CC) $(CFLAGS) -DPSCAT=1 -c -o $@ pscat.c
 
 pspipe: pspipe.o ../libpsargs/libpsargs.o
-	$(CC) $(CFLAGS) -g -o pspipe ../libpsargs/libpsargs.o pspipe.o
+	$(CC) $(CFLAGS) -o $@ pspipe.o ../libpsargs/libpsargs.o
 
-pspipe.o: pscat.c
-	$(CC) $(CFLAGS) -c -DPSPIPE=1 -I../libpsargs -o pspipe.o pscat.c
+pspipe.o: pscat.c psops.c
+	$(CC) $(CFLAGS) -DPSPIPE=1 -c -o $@ pscat.c
 
 ../libpsargs/libpsargs.o:
 	$(MAKE) -C ../libpsargs

pscat/pscat.c

@@ -1,17 +1,13 @@
 #include <errno.h> /* errno */
-#include <stdio.h> /* fprintf(3), stderr */
+#include <stdio.h> /* fprintf(3), stderr, "psops.c" */
 #include <string.h> /* strerror(3) */
-#include <sysexits.h> /* EX_USAGE */
+#include <sysexits.h> /* EX_OSERR, "psops.c" */
 #include <unistd.h> /* execvp(3) */
 #include <sys/types.h> /* <sys/wait.h> */
 #include <sys/wait.h> /* wait(2) */
 
-#include "libpsargs.h" /* check_arg(3), corresponding_arg(3) */
+#include "libpsargs.h" /* corresponding_arg(3), "psops.c" */
 
-#define L_PAREN '['
-#define R_PAREN ']'
-
-#if defined(PSCAT)
 static char *program_name = "pscat";
 
 int
@@ -19,7 +15,7 @@ f(char **argv){
 	int child;
 	char **corr;
 
-	*(corr = corresponding_arg(argv, L_PAREN, R_PAREN)) = NULL;
+	*(corr = corresponding_arg(argv)) = NULL;
 	switch(fork()){
 	case -1:
 		fprintf(stderr, "%s: %s\n", program_name, strerror(errno));
@@ -34,61 +30,4 @@ f(char **argv){
 	}
 }
 
-#elif defined(PSPIPE)
-static char *program_name = "pspipe";
-
-/* At the start of the loop argv[0] is { '[', '\0' } and file descriptor 0 is
- * the intended standard input */
-int
-f(char **argv){
-	int child;
-	char **corr;
-	static int fd[2];
-	int r;
-
-	*(corr = corresponding_arg(argv, L_PAREN, R_PAREN)) = NULL;
-	if(corr[1] != NULL){
-		if(pipe(fd) != 0){
-			fprintf(stderr,
-				"%s: %s: %s\n",
-				program_name, argv[1], strerror(errno)
-			);
-			return EX_OSERR;
-		}
-	}
-	if((r = fork()) == -1){
-		printf(stderr, "%s: %s\n", program_name, strerror(errno));
-		return EX_OSERR;
-	}
-	if(r == 0)
-		dup2(fd[0], 0);
-	else
-		dup2(fd[1], 1);
-
-	close(fd[1]);
-	close(fd[0]);
-
-	if(r == 1)
-		execvp(argv[1], argv+1);
-	else{
-		argv = corr;
-		return *++argv == NULL
-			? WIFEXITED(child) * WEXITSTATUS(child)
-			: f(argv);
-	}
-}
-
-#endif
-
-int main(int argc, char *argv[]){
-
-	if(argc != 0)
-		program_name = argv[0];
-	if(check_arg(++argv, L_PAREN, R_PAREN) == 0){
-		fprintf(stderr,
-			"Usage: %s \"[\" [utility [argument...]] \"]\" ...\n",
-			program_name
-		);
-		return EX_USAGE;
-	}else	return f(argv);
-}
+#include "psops.c"

pscat/psops.c

@@ -0,0 +1,20 @@
+/* #include <stdio.h> /* fprintf(3), stderr */
+
+#ifndef EX_USAGE
+#	define EX_USAGE 64 /* NetBSD sysexits(3) compat */
+#endif
+
+/* #include "libpsargs.h" /* check_arg(3) */
+
+int main(int argc, char *argv[]){
+
+	if(argc != 0)
+		program_name = argv[0];
+	if(check_arg(++argv) == 0){
+		fprintf(stderr,
+			"Usage: %s \"[\" [utility [argument...]] \"]\" ...\n",
+			program_name
+		);
+		return EX_USAGE;
+	}else	return f(argv);
+}

pscat/pspipe.c

@@ -0,0 +1,53 @@
+#include <errno.h> /* errno */
+#include <stdio.h> /* fprintf(3), stderr, "psops.c" */
+#include <string.h> /* strerror(3) */
+#include <sysexits.h> /* EX_OSERR */
+#include <unistd.h> /* execvp(3) */
+#include <sys/types.h> /* <sys/wait.h> */
+#include <sys/wait.h> /* wait(2) */
+
+#include "libpsargs.h" /* corresponding_arg(3), "psops.c" */
+
+static char *program_name = "pspipe";
+
+/* At the start of the loop argv[0] is { '[', '\0' } and file descriptor 0 is
+ * the intended standard input */
+int
+f(char **argv){
+	static int child;
+	char **corr;
+	int fd[2];
+	int r;
+
+	*(corr = corresponding_arg(argv)) = NULL;
+	if(corr[1] != NULL){
+		if(pipe(fd) != 0){
+			fprintf(stderr,
+				"%s: %s: %s\n",
+				program_name, argv[1], strerror(errno)
+			);
+			return EX_OSERR;
+		}
+		if((r = fork()) == -1){
+			fprintf(stderr, "%s: %s\n",
+				program_name, strerror(errno)
+			);
+			return EX_OSERR;
+		}
+		if(r == 0)
+			dup2(fd[0], 0);
+		else
+			dup2(fd[1], 1);
+		close(fd[1]);
+		close(fd[0]);
+		if(r == 1)
+			execvp(argv[1], argv+1);
+	}
+
+	argv = corr;
+	return *++argv == NULL
+		? WEXITSTATUS(child)
+		: f(corr + 1);
+}
+
+#include "psops.c"