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https://github.com/edk2-porting/linux-next.git
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21cfc5e103
This patch adds a fallback to cat for the pager. This is useful on environments, such as Android, where less does not exist. It is better to default to cat than to abort. Signed-off-by: Michael Lentine <mlentine@google.com> Reviewed-by: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1400579330-5043-2-git-send-email-eranian@google.com Signed-off-by: Jiri Olsa <jolsa@kernel.org>
101 lines
2.0 KiB
C
101 lines
2.0 KiB
C
#include "cache.h"
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#include "run-command.h"
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#include "sigchain.h"
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/*
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* This is split up from the rest of git so that we can do
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* something different on Windows.
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*/
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static int spawned_pager;
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static void pager_preexec(void)
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{
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/*
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* Work around bug in "less" by not starting it until we
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* have real input
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*/
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fd_set in;
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FD_ZERO(&in);
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FD_SET(0, &in);
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select(1, &in, NULL, &in, NULL);
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setenv("LESS", "FRSX", 0);
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}
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static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
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static struct child_process pager_process;
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static void wait_for_pager(void)
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{
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fflush(stdout);
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fflush(stderr);
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/* signal EOF to pager */
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close(1);
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close(2);
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finish_command(&pager_process);
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}
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static void wait_for_pager_signal(int signo)
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{
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wait_for_pager();
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sigchain_pop(signo);
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raise(signo);
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}
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void setup_pager(void)
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{
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const char *pager = getenv("PERF_PAGER");
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if (!isatty(1))
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return;
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if (!pager) {
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if (!pager_program)
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perf_config(perf_default_config, NULL);
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pager = pager_program;
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}
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if (!pager)
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pager = getenv("PAGER");
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if (!(pager || access("/usr/bin/pager", X_OK)))
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pager = "/usr/bin/pager";
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if (!(pager || access("/usr/bin/less", X_OK)))
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pager = "/usr/bin/less";
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if (!pager)
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pager = "cat";
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if (!*pager || !strcmp(pager, "cat"))
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return;
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spawned_pager = 1; /* means we are emitting to terminal */
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/* spawn the pager */
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pager_argv[2] = pager;
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pager_process.argv = pager_argv;
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pager_process.in = -1;
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pager_process.preexec_cb = pager_preexec;
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if (start_command(&pager_process))
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return;
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/* original process continues, but writes to the pipe */
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dup2(pager_process.in, 1);
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if (isatty(2))
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dup2(pager_process.in, 2);
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close(pager_process.in);
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/* this makes sure that the parent terminates after the pager */
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sigchain_push_common(wait_for_pager_signal);
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atexit(wait_for_pager);
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}
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int pager_in_use(void)
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{
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const char *env;
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if (spawned_pager)
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return 1;
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env = getenv("PERF_PAGER_IN_USE");
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return env ? perf_config_bool("PERF_PAGER_IN_USE", env) : 0;
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}
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