linux_dsm_epyc7002/tools/lib/subcmd/pager.c
Andi Kleen 61eb2eb434 perf tools: Query terminal width and use in perf list
Automatically adapt the now wider and word wrapped perf list output to
wider terminals. This requires querying the terminal before the auto
pager takes over, and exporting this information from the pager
subsystem.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1473978296-20712-8-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-10-03 21:35:45 -03:00

117 lines
2.2 KiB
C

#include <sys/select.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <sys/ioctl.h>
#include "pager.h"
#include "run-command.h"
#include "sigchain.h"
#include "subcmd-config.h"
/*
* This is split up from the rest of git so that we can do
* something different on Windows.
*/
static int spawned_pager;
static int pager_columns;
void pager_init(const char *pager_env)
{
subcmd_config.pager_env = pager_env;
}
static void pager_preexec(void)
{
/*
* Work around bug in "less" by not starting it until we
* have real input
*/
fd_set in;
FD_ZERO(&in);
FD_SET(0, &in);
select(1, &in, NULL, &in, NULL);
setenv("LESS", "FRSX", 0);
}
static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
static struct child_process pager_process;
static void wait_for_pager(void)
{
fflush(stdout);
fflush(stderr);
/* signal EOF to pager */
close(1);
close(2);
finish_command(&pager_process);
}
static void wait_for_pager_signal(int signo)
{
wait_for_pager();
sigchain_pop(signo);
raise(signo);
}
void setup_pager(void)
{
const char *pager = getenv(subcmd_config.pager_env);
struct winsize sz;
if (!isatty(1))
return;
if (ioctl(1, TIOCGWINSZ, &sz) == 0)
pager_columns = sz.ws_col;
if (!pager)
pager = getenv("PAGER");
if (!(pager || access("/usr/bin/pager", X_OK)))
pager = "/usr/bin/pager";
if (!(pager || access("/usr/bin/less", X_OK)))
pager = "/usr/bin/less";
if (!pager)
pager = "cat";
if (!*pager || !strcmp(pager, "cat"))
return;
spawned_pager = 1; /* means we are emitting to terminal */
/* spawn the pager */
pager_argv[2] = pager;
pager_process.argv = pager_argv;
pager_process.in = -1;
pager_process.preexec_cb = pager_preexec;
if (start_command(&pager_process))
return;
/* original process continues, but writes to the pipe */
dup2(pager_process.in, 1);
if (isatty(2))
dup2(pager_process.in, 2);
close(pager_process.in);
/* this makes sure that the parent terminates after the pager */
sigchain_push_common(wait_for_pager_signal);
atexit(wait_for_pager);
}
int pager_in_use(void)
{
return spawned_pager;
}
int pager_get_columns(void)
{
char *s;
s = getenv("COLUMNS");
if (s)
return atoi(s);
return (pager_columns ? pager_columns : 80) - 2;
}