shared/format-table: disable ellipsization when piped

Fixes #13461.

Before:
$ systemd-inhibit --no-pager
WHO            UID  USER    PID   COMM           WHAT                                  WHY          MODE
ModemManager   0    root    1093  ModemManager   sleep                                 ModemManage… delay
NetworkManager 0    root    1400  NetworkManager sleep                                 NetworkMana… delay
UPower         0    root    5141  upowerd        sleep                                 Pause devic… delay
zbyszek        1000 zbyszek 10036 gsd-power      handle-lid-switch                     External mo… block
zbyszek        1000 zbyszek 10035 gsd-media-keys handle-power-key:handle-suspend-key:… GNOME handl… block
zbyszek        1000 zbyszek 10035 gsd-media-keys sleep                                 GNOME handl… delay
zbyszek        1000 zbyszek 10036 gsd-power      sleep                                 GNOME needs… delay

7 inhibitors listed.
$ systemd-inhibit --no-pager|grep suspend
$ systemd-inhibit --no-pager|cat
WHO            UID  USER    PID   COMM           WHAT                WHY   MODE
ModemManager   0    root    1093  ModemManager   sleep               Mode… delay
NetworkManager 0    root    1400  NetworkManager sleep               Netw… delay
UPower         0    root    5141  upowerd        sleep               Paus… delay
zbyszek        1000 zbyszek 10036 gsd-power      handle-lid-switch   Exte… block
zbyszek        1000 zbyszek 10035 gsd-media-keys handle-power-key:h… GNOM… block
zbyszek        1000 zbyszek 10035 gsd-media-keys sleep               GNOM… delay
zbyszek        1000 zbyszek 10036 gsd-power      sleep               GNOM… delay

After:
$ build/systemd-inhibit --no-pager
(same as above)

$ build/systemd-inhibit --no-pager|grep suspend
zbyszek        1000 zbyszek 10035 gsd-media-keys handle-power-key:handle-suspend-key:handle-hibernate-key GNOME handling keypresses                                   block
$ build/systemd-inhibit --no-pager|cat
WHO            UID  USER    PID   COMM           WHAT                                                     WHY                                                         MODE
ModemManager   0    root    1093  ModemManager   sleep                                                    ModemManager needs to reset devices                         delay
NetworkManager 0    root    1400  NetworkManager sleep                                                    NetworkManager needs to turn off networks                   delay
UPower         0    root    5141  upowerd        sleep                                                    Pause device polling                                        delay
zbyszek        1000 zbyszek 10036 gsd-power      handle-lid-switch                                        External monitor attached or configuration changed recently block
zbyszek        1000 zbyszek 10035 gsd-media-keys handle-power-key:handle-suspend-key:handle-hibernate-key GNOME handling keypresses                                   block
zbyszek        1000 zbyszek 10035 gsd-media-keys sleep                                                    GNOME handling keypresses                                   delay
zbyszek        1000 zbyszek 10036 gsd-power      sleep                                                    GNOME needs to lock the screen                              delay

7 inhibitors listed.

Note that this affect all tools that use format-table.c: machinectl, busctl,
loginctl, systemd-analyze, networkctl, portablectl.

(cherry picked from commit 0db41a8f1f8eda49ce60e7efa23d17a5e24673e3)

2 files changed, 22 insertions, 9 deletions

diff --git a/src/shared/format-table.c b/src/shared/format-table.c
index e41cbb1720..4617ae8bad 100644
--- a/src/shared/format-table.c
+++ b/src/shared/format-table.c
@@ -2,6 +2,7 @@
 
 #include <ctype.h>
 #include <net/if.h>
+#include <unistd.h>
 
 #include "alloc-util.h"
 #include "fd-util.h"
@@ -1611,10 +1612,12 @@ int table_print(Table *t, FILE *f) {
         }
 
         /* Calculate effective table width */
-        if (t->width == (size_t) -1)
-                table_effective_width = pager_have() ? table_requested_width : MIN(table_requested_width, columns());
-        else
+        if (t->width != (size_t) -1)
                 table_effective_width = t->width;
+        else if (pager_have() || !isatty(STDOUT_FILENO))
+                table_effective_width = table_requested_width;
+        else
+                table_effective_width = MIN(table_requested_width, columns());
 
         if (table_maximum_width != (size_t) -1 && table_effective_width > table_maximum_width)
                 table_effective_width = table_maximum_width;
diff --git a/src/test/test-format-table.c b/src/test/test-format-table.c
index def9cbda2f..96b1d77701 100644
--- a/src/test/test-format-table.c
+++ b/src/test/test-format-table.c
@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
+#include <unistd.h>
+
 #include "alloc-util.h"
 #include "format-table.h"
 #include "string-util.h"
@@ -154,12 +156,20 @@ int main(int argc, char *argv[]) {
         assert_se(table_format(t, &formatted) >= 0);
         printf("%s\n", formatted);
 
-        assert_se(streq(formatted,
-                        "  no a long f…   no a long f… a long fi…\n"
-                        "  no fäää        no fäää      fäää      \n"
-                        " yes fäää       yes fäää      fäää      \n"
-                        " yes xxx        yes xxx       xxx       \n"
-                        "5min           5min                     \n"));
+        if (isatty(STDOUT_FILENO))
+                assert_se(streq(formatted,
+                                "  no a long f…   no a long f… a long fi…\n"
+                                "  no fäää        no fäää      fäää      \n"
+                                " yes fäää       yes fäää      fäää      \n"
+                                " yes xxx        yes xxx       xxx       \n"
+                                "5min           5min                     \n"));
+        else
+                assert_se(streq(formatted,
+                                "  no a long field   no a long field a long field\n"
+                                "  no fäää           no fäää         fäää        \n"
+                                " yes fäää          yes fäää         fäää        \n"
+                                " yes xxx           yes xxx          xxx         \n"
+                                "5min              5min                          \n"));
 
         test_issue_9549();