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>
		
			
				
	
	
		
			100 lines
		
	
	
	
		
			2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			100 lines
		
	
	
	
		
			2 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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