pager: tiny beautification

[elogind.git] / src / shared / pager.c

diff --git a/src/shared/pager.c b/src/shared/pager.c
index f1f3dc7e7edb41a3c5d9320ffa02b7557efe5217..184a0f57846dcb520ed79cd6fec9adc93bcafa36 100644 (file)
--- 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.
 
@@ -19,26 +17,34 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#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 "copy.h"
+#include "fd-util.h"
+#include "locale-util.h"
+#include "log.h"
+#include "macro.h"
 #include "pager.h"
-#include "util.h"
 #include "process-util.h"
-#include "macro.h"
-#include "terminal-util.h"
 #include "signal-util.h"
-#include "copy.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
 
 static pid_t pager_pid = 0;
 
 noreturn static void pager_fallback(void) {
         int r;
 
-        r = copy_bytes(STDIN_FILENO, STDOUT_FILENO, (off_t) -1, false);
+        r = copy_bytes(STDIN_FILENO, STDOUT_FILENO, (uint64_t) -1, false);
         if (r < 0) {
                 log_error_errno(r, "Internal pager failed: %m");
                 _exit(EXIT_FAILURE);
@@ -47,25 +53,31 @@ noreturn static void pager_fallback(void) {
         _exit(EXIT_SUCCESS);
 }
 
-int pager_open(bool jump_to_end) {
-        int fd[2];
+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;
 
-        if (!on_tty())
+        pager = getenv("SYSTEMD_PAGER");
+        if (!pager)
+                pager = getenv("PAGER");
+
+        /* 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)
                 return log_error_errno(errno, "Failed to create pager pipe: %m");
@@ -73,12 +85,8 @@ int pager_open(bool jump_to_end) {
         parent_pid = getpid();
 
         pager_pid = fork();
-        if (pager_pid < 0) {
-                r = -errno;
-                log_error_errno(errno, "Failed to fork pager: %m");
-                safe_close_pair(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) {
@@ -87,7 +95,7 @@ int pager_open(bool jump_to_end) {
                 (void) reset_all_signal_handlers();
                 (void) reset_signal_mask();
 
-                dup2(fd[0], STDIN_FILENO);
+                (void) dup2(fd[0], STDIN_FILENO);
                 safe_close_pair(fd);
 
                 /* Initialize a good set of less options */
@@ -142,7 +150,6 @@ int pager_open(bool jump_to_end) {
         if (dup2(fd[1], STDERR_FILENO) < 0)
                 return log_error_errno(errno, "Failed to duplicate pager pipe: %m");
 
-        safe_close_pair(fd);
         return 1;
 }
 
@@ -152,17 +159,15 @@ void pager_close(void) {
                 return;
 
         /* Inform pager that we are done */
-        fclose(stdout);
-#if defined(__GLIBC__)
-        stdout = NULL;
-#endif // in musl-libc this is a const
-
-        fclose(stderr);
-#if defined(__GLIBC__)
-        stderr = NULL;
-#endif // in musl-libc this is a const
-
-        kill(pager_pid, SIGCONT);
+#ifdef __GLIBC__
+        stdout = safe_fclose(stdout);
+        stderr = safe_fclose(stderr);
+#else
+        safe_fclose(stdout);
+        safe_fclose(stderr);
+#endif // __GLIBC__
+
+        (void) kill(pager_pid, SIGCONT);
         (void) wait_for_terminate(pager_pid, NULL);
         pager_pid = 0;
 }
@@ -171,8 +176,7 @@ bool pager_have(void) {
         return pager_pid > 0;
 }
 
-/// UNNEEDED by elogind
-#if 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;