Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "run-command.h"
   3#include "sigchain.h"
   4
   5#ifndef DEFAULT_PAGER
   6#define DEFAULT_PAGER "less"
   7#endif
   8
   9/*
  10 * This is split up from the rest of git so that we can do
  11 * something different on Windows.
  12 */
  13
  14static const char *pager_argv[] = { NULL, NULL };
  15static struct child_process pager_process = CHILD_PROCESS_INIT;
  16
  17static void wait_for_pager(void)
  18{
  19        fflush(stdout);
  20        fflush(stderr);
  21        /* signal EOF to pager */
  22        close(1);
  23        close(2);
  24        finish_command(&pager_process);
  25}
  26
  27static void wait_for_pager_signal(int signo)
  28{
  29        wait_for_pager();
  30        sigchain_pop(signo);
  31        raise(signo);
  32}
  33
  34const char *git_pager(int stdout_is_tty)
  35{
  36        const char *pager;
  37
  38        if (!stdout_is_tty)
  39                return NULL;
  40
  41        pager = getenv("GIT_PAGER");
  42        if (!pager) {
  43                if (!pager_program)
  44                        git_config(git_default_config, NULL);
  45                pager = pager_program;
  46        }
  47        if (!pager)
  48                pager = getenv("PAGER");
  49        if (!pager)
  50                pager = DEFAULT_PAGER;
  51        if (!*pager || !strcmp(pager, "cat"))
  52                pager = NULL;
  53
  54        return pager;
  55}
  56
  57void setup_pager(void)
  58{
  59        const char *pager = git_pager(isatty(1));
  60
  61        if (!pager)
  62                return;
  63
  64        /*
  65         * force computing the width of the terminal before we redirect
  66         * the standard output to the pager.
  67         */
  68        (void) term_columns();
  69
  70        setenv("GIT_PAGER_IN_USE", "true", 1);
  71
  72        /* spawn the pager */
  73        pager_argv[0] = pager;
  74        pager_process.use_shell = 1;
  75        pager_process.argv = pager_argv;
  76        pager_process.in = -1;
  77        if (!getenv("LESS") || !getenv("LV")) {
  78                static const char *env[3];
  79                int i = 0;
  80
  81                if (!getenv("LESS"))
  82                        env[i++] = "LESS=FRX";
  83                if (!getenv("LV"))
  84                        env[i++] = "LV=-c";
  85                env[i] = NULL;
  86                pager_process.env = env;
  87        }
  88        if (start_command(&pager_process))
  89                return;
  90
  91        /* original process continues, but writes to the pipe */
  92        dup2(pager_process.in, 1);
  93        if (isatty(2))
  94                dup2(pager_process.in, 2);
  95        close(pager_process.in);
  96
  97        /* this makes sure that the parent terminates after the pager */
  98        sigchain_push_common(wait_for_pager_signal);
  99        atexit(wait_for_pager);
 100}
 101
 102int pager_in_use(void)
 103{
 104        const char *env;
 105        env = getenv("GIT_PAGER_IN_USE");
 106        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 107}
 108
 109/*
 110 * Return cached value (if set) or $COLUMNS environment variable (if
 111 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
 112 * and default to 80 if all else fails.
 113 */
 114int term_columns(void)
 115{
 116        static int term_columns_at_startup;
 117
 118        char *col_string;
 119        int n_cols;
 120
 121        if (term_columns_at_startup)
 122                return term_columns_at_startup;
 123
 124        term_columns_at_startup = 80;
 125
 126        col_string = getenv("COLUMNS");
 127        if (col_string && (n_cols = atoi(col_string)) > 0)
 128                term_columns_at_startup = n_cols;
 129#ifdef TIOCGWINSZ
 130        else {
 131                struct winsize ws;
 132                if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
 133                        term_columns_at_startup = ws.ws_col;
 134        }
 135#endif
 136
 137        return term_columns_at_startup;
 138}
 139
 140/*
 141 * How many columns do we need to show this number in decimal?
 142 */
 143int decimal_width(int number)
 144{
 145        int i, width;
 146
 147        for (width = 1, i = 10; i <= number; width++)
 148                i *= 10;
 149        return width;
 150}
 151
 152/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
 153int check_pager_config(const char *cmd)
 154{
 155        int want = -1;
 156        struct strbuf key = STRBUF_INIT;
 157        const char *value = NULL;
 158        strbuf_addf(&key, "pager.%s", cmd);
 159        if (!git_config_get_value(key.buf, &value)) {
 160                int b = git_config_maybe_bool(key.buf, value);
 161                if (b >= 0)
 162                        want = b;
 163                else {
 164                        want = 1;
 165                        pager_program = xstrdup(value);
 166                }
 167        }
 168        strbuf_release(&key);
 169        return want;
 170}