Include strerror(errno) in error messages after failed system calls.

Fix a warning.

bin/sh/cd.c

@@ -342,7 +342,7 @@ getpwd()
 
 		INTOFF;
 		if (pipe(pip) < 0)
-			error("Pipe call failed");
+			error("Pipe call failed: %s", strerror(errno));
 		jp = makejob((union node *)NULL, 1);
 		if (forkshell(jp, (union node *)NULL, FORK_NOJOB) == 0) {
 			(void) close(pip[0]);

bin/sh/error.c

@@ -51,6 +51,7 @@ static const char rcsid[] =
 #include "options.h"
 #include "output.h"
 #include "error.h"
+#include "nodes.h" /* show.h needs nodes.h */
 #include "show.h"
 #include "trap.h"
 #include <signal.h>

bin/sh/eval.c

@@ -45,6 +45,7 @@ static const char rcsid[] =
 #include <signal.h>
 #include <unistd.h>
 #include <sys/wait.h> /* For WIFSIGNALED(status) */
+#include <errno.h>
 
 /*
  * Evaluate a command.
@@ -488,7 +489,7 @@ evalpipe(n)
 		if (lp->next) {
 			if (pipe(pip) < 0) {
 				close(prevfd);
-				error("Pipe call failed");
+				error("Pipe call failed: %s", strerror(errno));
 			}
 		}
 		if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
@@ -556,7 +557,7 @@ evalbackcmd(n, result)
 	} else {
 		exitstatus = 0;
 		if (pipe(pip) < 0)
-			error("Pipe call failed");
+			error("Pipe call failed: %s", strerror(errno));
 		jp = makejob(n, 1);
 		if (forkshell(jp, n, FORK_NOJOB) == 0) {
 			FORCEINTON;
@@ -728,7 +729,7 @@ evalcommand(cmd, flags, backcmd)
 		if (flags & EV_BACKCMD) {
 			mode = FORK_NOJOB;
 			if (pipe(pip) < 0)
-				error("Pipe call failed");
+				error("Pipe call failed: %s", strerror(errno));
 		}
 		if (forkshell(jp, cmd, mode) != 0)
 			goto parent;	/* at end of routine */

bin/sh/input.c

@@ -383,7 +383,7 @@ setinputfile(fname, push)
 
 	INTOFF;
 	if ((fd = open(fname, O_RDONLY)) < 0)
-		error("Can't open %s", fname);
+		error("Can't open %s: %s", fname, strerror(errno));
 	if (fd < 10) {
 		fd2 = copyfd(fd, 10);
 		close(fd);

bin/sh/jobs.c

@@ -594,7 +594,7 @@ forkshell(jp, n, mode)
 	if (pid == -1) {
 		TRACE(("Fork failed, errno=%d\n", errno));
 		INTON;
-		error("Cannot fork");
+		error("Cannot fork: %s", strerror(errno));
 	}
 	if (pid == 0) {
 		struct job *p;
@@ -636,7 +636,8 @@ forkshell(jp, n, mode)
 			    ! fd0_redirected_p ()) {
 				close(0);
 				if (open("/dev/null", O_RDONLY) != 0)
-					error("Can't open /dev/null");
+					error("Can't open /dev/null: %s", 
+					    strerror(errno));
 			}
 		}
 #else
@@ -647,7 +648,8 @@ forkshell(jp, n, mode)
 			    ! fd0_redirected_p ()) {
 				close(0);
 				if (open("/dev/null", O_RDONLY) != 0)
-					error("Can't open /dev/null");
+					error("Can't open /dev/null: %s", 
+					    strerror(errno));
 			}
 		}
 #endif

bin/sh/main.c

@@ -300,7 +300,7 @@ readcmdfile(name)
 	if ((fd = open(name, O_RDONLY)) >= 0)
 		setinputfd(fd, 1);
 	else
-		error("Can't open %s", name);
+		error("Can't open %s: %s", name, strerror(errno));
 	INTON;
 	cmdloop(0);
 	popfile();

bin/sh/mkinit.c

@@ -66,6 +66,7 @@ static const char rcsid[] =
 #include <string.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <errno.h>
 
 
 /*
@@ -478,7 +479,7 @@ ckfopen(file, mode)
 	FILE *fp;
 
 	if ((fp = fopen(file, mode)) == NULL) {
-		fprintf(stderr, "Can't open %s\n", file);
+		fprintf(stderr, "Can't open %s: %s\n", file, strerror(errno));
 		exit(2);
 	}
 	return fp;

bin/sh/mknodes.c

@@ -56,6 +56,7 @@ static const char rcsid[] =
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 #ifdef __STDC__
 #include <stdarg.h>
 #else
@@ -123,7 +124,7 @@ main(argc, argv)
 	if (argc != 3)
 		error("usage: mknodes file");
 	if ((infp = fopen(argv[1], "r")) == NULL)
-		error("Can't open %s", argv[1]);
+		error("Can't open %s: %s", argv[1], strerror(errno));
 	while (readline()) {
 		if (line[0] == ' ' || line[0] == '\t')
 			parsefield();
@@ -232,9 +233,9 @@ output(file)
 	char *p;
 
 	if ((patfile = fopen(file, "r")) == NULL)
-		error("Can't open %s", file);
+		error("Can't open %s: %s", file, strerror(errno));
 	if ((hfile = fopen("nodes.h", "w")) == NULL)
-		error("Can't create nodes.h");
+		error("Can't create nodes.h: %s", strerror(errno));
 	if ((cfile = fopen("nodes.c", "w")) == NULL)
 		error("Can't create nodes.c");
 	fputs(writer, hfile);

bin/sh/redir.c

@@ -246,7 +246,7 @@ openhere(redir)
 	int len = 0;
 
 	if (pipe(pip) < 0)
-		error("Pipe call failed");
+		error("Pipe call failed: %s", strerror(errno));
 	if (redir->type == NHERE) {
 		len = strlen(redir->nhere.doc->narg.text);
 		if (len <= PIPESIZE) {

bin/sh/show.c

@@ -420,7 +420,7 @@ opentrace() {
 	scopy("./trace", s);
 #endif /* not_this_way */
 	if ((tracefile = fopen(s, "a")) == NULL) {
-		fprintf(stderr, "Can't open %s\n", s);
+		fprintf(stderr, "Can't open %s: %s\n", s, strerror(errno));
 		return;
 	}
 #ifdef O_APPEND