Add pager functionality

client/tarantool/CMakeLists.txt

@@ -9,7 +9,7 @@ endif()
 
 set (cli "tarantool")
 set (cli_sources tc.c tc_opt.c tc_admin.c tc_query.c tc_print.c tc_buf.c
-		tc_cli.c tc_store.c tc_print_xlog.c tc_print_snap.c)
+		tc_cli.c tc_store.c tc_print_xlog.c tc_print_snap.c tc_pager.c)
 set (cli_libs tntrpl tntnet tntsql tnt gopt ${READLINE_LIBRARIES})
 
 include_directories(${READLINE_INCLUDE_DIR})

client/tarantool/tc.c

@@ -43,6 +43,7 @@
 #include "client/tarantool/tc_opt.h"
 #include "client/tarantool/tc_admin.h"
 #include "client/tarantool/tc.h"
+#include "client/tarantool/tc_pager.h"
 #include "client/tarantool/tc_cli.h"
 #include "client/tarantool/tc_print.h"
 #include "client/tarantool/tc_store.h"
@@ -57,13 +58,15 @@ struct tc tc;
 static void tc_init(void) {
 	memset(&tc, 0, sizeof(tc));
 	setlocale(LC_ALL, "");
+	tc.pager_fd = fileno(stdout);
+	tc.pager_pid = 0;
 }
 
 static void tc_free(void) {
-	if (tc.net) {
+	if (tc.net)
 		tnt_stream_free(tc.net);
-	}
 	tc_admin_close(&tc.admin);
+	tc_pager_kill();
 }
 
 void tc_error(char *fmt, ...) {

client/tarantool/tc.h

@@ -33,6 +33,8 @@ struct tc {
 	struct tc_opt opt;
 	struct tc_admin admin;
 	struct tnt_stream *net;
+	int pager_fd;
+	pid_t pager_pid;
 };
 
 void tc_error(char *fmt, ...);

client/tarantool/tc_cli.c

@@ -57,6 +57,7 @@
 #include "client/tarantool/tc_opt.h"
 #include "client/tarantool/tc_admin.h"
 #include "client/tarantool/tc.h"
+#include "client/tarantool/tc_pager.h"
 #include "client/tarantool/tc_query.h"
 #include "client/tarantool/tc_cli.h"
 #include "client/tarantool/tc_print.h"
@@ -95,24 +96,26 @@ enum tc_keywords {
 	TC_LOADFILE,
 	TC_HELP,
 	TC_SETOPT,
-	TC_SETOPT_DELIM
+	TC_SETOPT_DELIM,
+	TC_SETOPT_PAGER
 };
 
 static struct tnt_lex_keyword tc_lex_keywords[] =
 {
-	{ "e", 1, TC_EXIT },
-	{ "ex", 2, TC_EXIT },
-	{ "exi", 3, TC_EXIT },
-	{ "exit", 4, TC_EXIT },
-	{ "q", 1, TC_EXIT },
-	{ "qu", 2, TC_EXIT },
-	{ "qui", 3, TC_EXIT },
-	{ "quit", 4, TC_EXIT },
-	{ "help", 4, TC_HELP },
-	{ "loadfile", 8, TC_LOADFILE },
-	{ "setopt", 6, TC_SETOPT},
-	{ "delimiter", 9, TC_SETOPT_DELIM},
-	{ NULL, 0, TNT_TK_NONE }
+	{ "e",         1, TC_EXIT         },
+	{ "ex",        2, TC_EXIT         },
+	{ "exi",       3, TC_EXIT         },
+	{ "exit",      4, TC_EXIT         },
+	{ "q",         1, TC_EXIT         },
+	{ "qu",        2, TC_EXIT         },
+	{ "qui",       3, TC_EXIT         },
+	{ "quit",      4, TC_EXIT         },
+	{ "help",      4, TC_HELP         },
+	{ "loadfile",  8, TC_LOADFILE     },
+	{ "setopt",    6, TC_SETOPT       },
+	{ "delimiter", 9, TC_SETOPT_DELIM },
+	{ "pager",     5, TC_SETOPT_PAGER },
+	{ NULL,        0, TNT_TK_NONE     }
 };
 
 enum tc_cli_cmd_ret {
@@ -130,7 +133,8 @@ tc_cmd_usage(void)
 		" - help\n"
 		" - loadfile 'path'\n"
 		" - setopt key=val\n"
-		" - (possible pairs: delim=\'str\')\n"
+		" - (possible pairs: delimiter = \'string\'  )\n"
+		" - (                pager     = \'command\' )\n"
 		"...\n";
 	tc_printf("%s", usage);
 }
@@ -138,8 +142,10 @@ tc_cmd_usage(void)
 static int tc_cli_admin(char *cmd, int exit) {
 	char *e = NULL;
 	tc_query_admin_t cb = (exit) ? NULL : tc_query_admin_printer;
+	tc_pager_start();
 	if (tc_query_admin(cmd, cb, &e) == -1)
 		return tc_cli_error(e);
+	tc_pager_stop();
 	return 0;
 }
 
@@ -247,7 +253,29 @@ tc_cmd_try(char *cmd, size_t size, int *reconnect)
 				tc.opt.delim_len = strlen(tc.opt.delim);
 			} else {
 				tc_printf("---\n");
-				tc_printf(" - Expected delim='string'\n");
+				tc_printf(" - Expected delimiter='string'\n");
+				tc_printf("---\n");
+			}
+			break;
+		case TC_SETOPT_PAGER:
+			if (tnt_lex(&lex, &tk) == '=' &&
+			    tnt_lex(&lex, &tk) == TNT_TK_STRING) {
+				if (!TNT_TK_S(tk)->size) {
+					tc.opt.pager = NULL;
+					goto done;
+				}
+				char * temp = (char *)malloc(TNT_TK_S(tk)->size);
+				if (temp == NULL)
+					tc_error(TC_ALLOCATION_ERROR,
+						 TNT_TK_S(tk)->size);
+				strncpy(temp,
+					(const char *)TNT_TK_S(tk)->data,
+					TNT_TK_S(tk)->size + 1);
+				temp[TNT_TK_S(tk)->size] = '\0';
+				tc.opt.pager = temp;
+			} else {
+				tc_printf("---\n");
+				tc_printf(" - Expected pager='command'\n");
 				tc_printf("---\n");
 			}
 			break;
@@ -277,12 +305,14 @@ static enum tc_cli_cmd_ret tc_cli_cmd(char *cmd, size_t size)
 		}
 		char *e = NULL;
 		if (tnt_query_is(cmd, size)) {
+			tc_pager_start();
 			if (tc_query(cmd, &e) == 0) {
 				if (tc_query_foreach(tc_query_printer, NULL, &e) == -1)
 					reconnect = tc_cli_error(e);
 			} else {
 				reconnect = tc_cli_error(e);
 			}
+			tc_pager_stop();
 			/* reconnect only for network errors */
 			if (reconnect && tnt_error(tc.net) != TNT_ESYSTEM)
 				reconnect = 0;

client/tarantool/tc_opt.c

@@ -196,6 +196,7 @@ enum tc_opt_mode tc_opt_init(struct tc_opt *opt, int argc, char **argv)
 	} else {
 		opt->mode = TC_OPT_INTERACTIVE;
 	}
+	opt->pager = NULL;
 done:
 	gopt_free(tc_options);
 	return opt->mode;

client/tarantool/tc_opt.h

@@ -65,6 +65,7 @@ struct tc_opt {
 	int cmdc;
 	const char *delim;
 	size_t delim_len;
+	const char *pager;
 };
 
 void tc_opt_usage(void);

client/tarantool/tc_pager.c

+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "client/tarantool/tc_opt.h"
+#include "client/tarantool/tc_admin.h"
+#include "client/tarantool/tc.h"
+#include "client/tarantool/tc_pager.h"
+
+extern struct tc tc;
+
+void tc_pager_start() {
+	if (tc.pager_pid != 0)
+		tc_pager_kill();
+	if (tc.opt.pager == NULL) {
+		tc.pager_fd = fileno(stdout);
+		return;
+	}
+	char cmd[] = {"/bin/bash"};
+	char args[] = {"-c"};
+	int pipefd[2];
+	const char *const argv[] = {cmd, args, tc.opt.pager, NULL};
+
+
+	if (pipe(pipefd) < 0)
+		tc_error("Failed to open pipe. Errno: %d", errno);
+	pid_t pid = fork();
+	if (pid < 0)
+		tc_error("Failed to fork. Errno: %d", errno);
+	if (pid == 0) {
+		close(pipefd[1]);
+		dup2(pipefd[0], STDIN_FILENO);
+		execve(argv[0], (char * const*)argv, NULL);
+		tc_error("Can't start pager! Errno: %d", errno);
+	}
+	close(pipefd[0]);
+	tc.pager_fd = pipefd[1];
+	tc.pager_pid = pid;
+	return;
+}
+
+void tc_pager_stop () {
+	if (tc.pager_pid != 0) {
+		close(tc.pager_fd);
+		tc.pager_fd = fileno(stdout);
+		waitpid(tc.pager_pid, NULL, 0);
+		tc.pager_pid = 0;
+	}
+	return;
+}
+
+void tc_pager_kill () {
+	if (tc.pager_pid != 0) {
+		kill(tc.pager_pid, SIGTERM);
+		tc_pager_stop();
+	}
+}

client/tarantool/tc_pager.h

+#ifndef TC_PAGER_H_INCLUDED
+#define TC_PAGER_H_INCLUDED
+/*
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above
+ *    copyright notice, this list of conditions and the
+ *    following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+void tc_pager_start();
+void tc_pager_stop();
+void tc_pager_kill();
+#endif /* TC_PAGER_H_INCLUDED */

client/tarantool/tc_print.c

@@ -57,9 +57,15 @@ void tc_print_buf(char *buf, size_t size) {
 }
 
 void tc_printf(char *fmt, ...) {
+	char *str;
 	va_list args;
 	va_start(args, fmt);
-	vprintf(fmt, args);
+	ssize_t str_len = vasprintf(&str, fmt, args);
+	if (str_len == -1)
+		tc_error("Error in vasprintf - %d", errno);
+	ssize_t stat = write(tc.pager_fd, str, str_len);
+	if (stat == -1)
+		tc_error("Can't write into pager - %d", errno);
 	va_end(args);
 	return;
 }