X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Fpager.c;h=8f3fc133ba29dab4899ace53d5cbe1c145e8bb99;hp=e9aa022a73fe3718f5ebf53935a5a80bf1d88a42;hb=d5673993ad3bf38d0aeba8dbd025d6f4527f0169;hpb=a4c41bf3fa905c38e6e4d159c13eed890d53838b

diff --git a/src/shared/pager.c b/src/shared/pager.c
index e9aa022a7..8f3fc133b 100644
--- a/src/shared/pager.c
+++ b/src/shared/pager.c
@@ -1,5 +1,3 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
 /***
   This file is part of systemd.
 
@@ -19,76 +17,110 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <sys/types.h>
-#include <fcntl.h>
+#include <errno.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include <string.h>
 #include <sys/prctl.h>
+#include <unistd.h>
 
-#include "pager.h"
-#include "util.h"
+#include "copy.h"
+#include "fd-util.h"
+#include "locale-util.h"
+#include "log.h"
 #include "macro.h"
+#include "pager.h"
+#include "process-util.h"
+#include "signal-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
 
 static pid_t pager_pid = 0;
 
-_noreturn_ static void pager_fallback(void) {
-        ssize_t n;
-        do {
-                n = splice(STDIN_FILENO, NULL, STDOUT_FILENO, NULL, 64*1024, 0);
-        } while (n > 0);
-        if (n < 0) {
-                log_error("Internal pager failed: %m");
+noreturn static void pager_fallback(void) {
+        int r;
+
+        r = copy_bytes(STDIN_FILENO, STDOUT_FILENO, (uint64_t) -1, 0);
+        if (r < 0) {
+                log_error_errno(r, "Internal pager failed: %m");
                 _exit(EXIT_FAILURE);
         }
+
         _exit(EXIT_SUCCESS);
 }
 
-int pager_open(bool jump_to_end) {
-        int fd[2];
+static int stored_stdout = -1;
+static int stored_stderr = -1;
+static bool stdout_redirected = false;
+static bool stderr_redirected = false;
+
+int pager_open(bool no_pager, bool jump_to_end) {
+        _cleanup_close_pair_ int fd[2] = { -1, -1 };
         const char *pager;
         pid_t parent_pid;
-        int r;
+
+        if (no_pager)
+                return 0;
 
         if (pager_pid > 0)
                 return 1;
 
-        if ((pager = getenv("SYSTEMD_PAGER")) || (pager = getenv("PAGER")))
-                if (!*pager || streq(pager, "cat"))
-                        return 0;
+        if (terminal_is_dumb())
+                return 0;
+
+        pager = getenv("SYSTEMD_PAGER");
+        if (!pager)
+                pager = getenv("PAGER");
 
-        if (!on_tty())
+        /* If the pager is explicitly turned off, honour it */
+        if (pager && STR_IN_SET(pager, "", "cat"))
                 return 0;
 
         /* Determine and cache number of columns before we spawn the
          * pager so that we get the value from the actual tty */
-        columns();
+        (void) columns();
 
-        if (pipe(fd) < 0) {
-                log_error("Failed to create pager pipe: %m");
-                return -errno;
-        }
+        if (pipe(fd) < 0)
+                return log_error_errno(errno, "Failed to create pager pipe: %m");
 
         parent_pid = getpid();
 
         pager_pid = fork();
-        if (pager_pid < 0) {
-                r = -errno;
-                log_error("Failed to fork pager: %m");
-                close_pipe(fd);
-                return r;
-        }
+        if (pager_pid < 0)
+                return log_error_errno(errno, "Failed to fork pager: %m");
 
         /* In the child start the pager */
         if (pager_pid == 0) {
+                const char* less_opts, *less_charset;
+
+                (void) reset_all_signal_handlers();
+                (void) reset_signal_mask();
 
-                dup2(fd[0], STDIN_FILENO);
-                close_pipe(fd);
+                (void) dup2(fd[0], STDIN_FILENO);
+                safe_close_pair(fd);
 
+                /* Initialize a good set of less options */
+                less_opts = getenv("SYSTEMD_LESS");
+                if (!less_opts)
+                        less_opts = "FRSXMK";
                 if (jump_to_end)
-                        setenv("LESS", "FRSXK+G", 1);
-                else
-                        setenv("LESS", "FRSXK", 1);
+                        less_opts = strjoina(less_opts, " +G");
+                if (setenv("LESS", less_opts, 1) < 0)
+                        _exit(EXIT_FAILURE);
+
+                /* Initialize a good charset for less. This is
+                 * particularly important if we output UTF-8
+                 * characters. */
+                less_charset = getenv("SYSTEMD_LESSCHARSET");
+                if (!less_charset && is_locale_utf8())
+                        less_charset = "utf-8";
+                if (less_charset &&
+                    setenv("LESSCHARSET", less_charset, 1) < 0)
+                        _exit(EXIT_FAILURE);
 
                 /* Make sure the pager goes away when the parent dies */
                 if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
@@ -120,12 +152,20 @@ int pager_open(bool jump_to_end) {
         }
 
         /* Return in the parent */
+        stored_stdout = fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 3);
         if (dup2(fd[1], STDOUT_FILENO) < 0) {
-                log_error("Failed to duplicate pager pipe: %m");
-                return -errno;
+                stored_stdout = safe_close(stored_stdout);
+                return log_error_errno(errno, "Failed to duplicate pager pipe: %m");
         }
+        stdout_redirected = true;
+
+        stored_stderr = fcntl(STDERR_FILENO, F_DUPFD_CLOEXEC, 3);
+        if (dup2(fd[1], STDERR_FILENO) < 0) {
+                stored_stderr = safe_close(stored_stderr);
+                return log_error_errno(errno, "Failed to duplicate pager pipe: %m");
+        }
+        stderr_redirected = true;
 
-        close_pipe(fd);
         return 1;
 }
 
@@ -135,12 +175,80 @@ void pager_close(void) {
                 return;
 
         /* Inform pager that we are done */
-        fclose(stdout);
-        kill(pager_pid, SIGCONT);
-        wait_for_terminate(pager_pid, NULL);
+        (void) fflush(stdout);
+        if (stdout_redirected)
+                if (stored_stdout < 0 || dup2(stored_stdout, STDOUT_FILENO) < 0)
+                        (void) close(STDOUT_FILENO);
+        stored_stdout = safe_close(stored_stdout);
+        (void) fflush(stderr);
+        if (stderr_redirected)
+                if (stored_stderr < 0 || dup2(stored_stderr, STDERR_FILENO) < 0)
+                        (void) close(STDERR_FILENO);
+        stored_stderr = safe_close(stored_stderr);
+        stdout_redirected = stderr_redirected = false;
+
+        (void) kill(pager_pid, SIGCONT);
+        (void) wait_for_terminate(pager_pid, NULL);
         pager_pid = 0;
 }
 
 bool pager_have(void) {
         return pager_pid > 0;
 }
+
+#if 0 /// UNNEEDED by elogind
+int show_man_page(const char *desc, bool null_stdio) {
+        const char *args[4] = { "man", NULL, NULL, NULL };
+        char *e = NULL;
+        pid_t pid;
+        size_t k;
+        int r;
+        siginfo_t status;
+
+        k = strlen(desc);
+
+        if (desc[k-1] == ')')
+                e = strrchr(desc, '(');
+
+        if (e) {
+                char *page = NULL, *section = NULL;
+
+                page = strndupa(desc, e - desc);
+                section = strndupa(e + 1, desc + k - e - 2);
+
+                args[1] = section;
+                args[2] = page;
+        } else
+                args[1] = desc;
+
+        pid = fork();
+        if (pid < 0)
+                return log_error_errno(errno, "Failed to fork: %m");
+
+        if (pid == 0) {
+                /* Child */
+
+                (void) reset_all_signal_handlers();
+                (void) reset_signal_mask();
+
+                if (null_stdio) {
+                        r = make_null_stdio();
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to kill stdio: %m");
+                                _exit(EXIT_FAILURE);
+                        }
+                }
+
+                execvp(args[0], (char**) args);
+                log_error_errno(errno, "Failed to execute man: %m");
+                _exit(EXIT_FAILURE);
+        }
+
+        r = wait_for_terminate(pid, &status);
+        if (r < 0)
+                return r;
+
+        log_debug("Exit code %i status %i", status.si_code, status.si_status);
+        return status.si_status;
+}
+#endif // 0