dmesg: use $PAGER for --human output, add --nopager

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/dmesg.1 b/sys-utils/dmesg.1
index b9bdf406e1ca2fd3476eb1b2b32747e390730dd7..f2dcc1c24d4169f209c86e3e1c1e2c2c32a491dc 100644 (file)
--- a/sys-utils/dmesg.1
+++ b/sys-utils/dmesg.1
@@ -57,7 +57,8 @@ see
 .B dmesg \-\-help
 output.
 .IP "\fB\-H\fR, \fB\-\-human\fR"
-Enable human readable output.
+Enable human readable output.  See also \fB\-\-color\fR, \fB\-\-reltime\fR
+and \fB\-\-nopager\fR.
 .IP "\fB\-h\fR, \fB\-\-help\fR"
 Print a help text and exit.
 .IP "\fB\-k\fR, \fB\-\-kernel\fR"
@@ -102,6 +103,8 @@ option is used,
 will
 .I not
 print or clear the kernel ring buffer.
+.IP "\fB\-P\fR, \fB\-\-nopager\fR"
+Do not pipe output into a pager, the pager is enabled for \fB\-\-human\fR output.
 .IP "\fB\-r\fR, \fB\-\-raw\fR"
 Print the raw message buffer, i.e., do not strip the log level prefixes.
 

diff --git a/sys-utils/dmesg.c b/sys-utils/dmesg.c
index 4076cf6b563dcbefd847090bf21b46e228c015c9..3387ea4b97131b28d457c9513c66f368a8f041a4 100644 (file)
--- a/sys-utils/dmesg.c
+++ b/sys-utils/dmesg.c
@@ -33,6 +33,7 @@
 #include "closestream.h"
 #include "optutils.h"
 #include "mangle.h"
+#include "pager.h"
 
 /* Close the log.  Currently a NOP. */
 #define SYSLOG_ACTION_CLOSE          0
@@ -161,6 +162,7 @@ struct dmesg_control {
                        delta:1,        /* show time deltas */
                        reltime:1,      /* show human readable relative times */
                        ctime:1,        /* show human readable time */
+                       pager:1,        /* pipe output into a pager */
                        color:1;        /* colorize messages */
 };
 
@@ -237,6 +239,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
        fputs(_(" -L, --color                 colorize messages\n"), out);
        fputs(_(" -l, --level <list>          restrict output to defined levels\n"), out);
        fputs(_(" -n, --console-level <level> set level of messages printed to console\n"), out);
+       fputs(_(" -P, --nopager               do not pipe output into a pager\n"), out);
        fputs(_(" -r, --raw                   print the raw message buffer\n"), out);
        fputs(_(" -S, --syslog                force to use syslog(2) rather than /dev/kmsg\n"), out);
        fputs(_(" -s, --buffer-size <size>    buffer size to query the kernel ring buffer\n"), out);
@@ -1139,7 +1142,7 @@ static int read_kmsg(struct dmesg_control *ctl)
 int main(int argc, char *argv[])
 {
        char *buf = NULL;
-       int  c;
+       int  c, nopager = 0;
        int  console_level = 0;
        int  klog_rc = 0;
        ssize_t n;
@@ -1172,6 +1175,7 @@ int main(int argc, char *argv[])
                { "show-delta",    no_argument,       NULL, 'd' },
                { "ctime",         no_argument,       NULL, 'T' },
                { "notime",        no_argument,       NULL, 't' },
+               { "nopager",       no_argument,       NULL, 'P' },
                { "userspace",     no_argument,       NULL, 'u' },
                { "version",       no_argument,       NULL, 'V' },
                { NULL,            0, NULL, 0 }
@@ -1191,7 +1195,7 @@ int main(int argc, char *argv[])
        textdomain(PACKAGE);
        atexit(close_stdout);
 
-       while ((c = getopt_long(argc, argv, "CcDdEeF:f:HhkLl:n:rSs:TtuVwx",
+       while ((c = getopt_long(argc, argv, "CcDdEeF:f:HhkLl:n:iPrSs:TtuVwx",
                                longopts, NULL)) != -1) {
 
                err_exclusive_options(c, longopts, excl, excl_st);
@@ -1228,6 +1232,7 @@ int main(int argc, char *argv[])
                case 'H':
                        ctl.reltime = 1;
                        ctl.color = 1;
+                       ctl.pager = 1;
                        break;
                case 'h':
                        usage(stdout);
@@ -1249,6 +1254,9 @@ int main(int argc, char *argv[])
                        ctl.action = SYSLOG_ACTION_CONSOLE_LEVEL;
                        console_level = parse_level(optarg, 0);
                        break;
+               case 'P':
+                       nopager = 1;
+                       break;
                case 'r':
                        ctl.raw = 1;
                        break;
@@ -1310,16 +1318,20 @@ int main(int argc, char *argv[])
                if (!ctl.boot_time)
                        ctl.reltime = 0;
        }
-
        if (ctl.color)
                ctl.color = colors_init() ? 1 : 0;
 
+       ctl.pager = nopager ? 0 : ctl.pager;
+       if (ctl.pager)
+               setup_pager();
+
        switch (ctl.action) {
        case SYSLOG_ACTION_READ_ALL:
        case SYSLOG_ACTION_READ_CLEAR:
                if (ctl.method == DMESG_METHOD_KMSG && init_kmsg(&ctl) != 0)
                        ctl.method = DMESG_METHOD_SYSLOG;
-
+               if (ctl.pager)
+                       setup_pager();
                n = read_buffer(&ctl, &buf);
                if (n > 0)
                        print_buffer(&ctl, buf, n);