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 struct child_process pager_process = CHILD_PROCESS_INIT;
  15
  16static void wait_for_pager(int in_signal)
  17{
  18        if (!in_signal) {
  19                fflush(stdout);
  20                fflush(stderr);
  21        }
  22        /* signal EOF to pager */
  23        close(1);
  24        close(2);
  25        if (in_signal)
  26                finish_command_in_signal(&pager_process);
  27        else
  28                finish_command(&pager_process);
  29}
  30
  31static void wait_for_pager_atexit(void)
  32{
  33        wait_for_pager(0);
  34}
  35
  36static void wait_for_pager_signal(int signo)
  37{
  38        wait_for_pager(1);
  39        sigchain_pop(signo);
  40        raise(signo);
  41}
  42
  43const char *git_pager(int stdout_is_tty)
  44{
  45        const char *pager;
  46
  47        if (!stdout_is_tty)
  48                return NULL;
  49
  50        pager = getenv("GIT_PAGER");
  51        if (!pager) {
  52                if (!pager_program)
  53                        git_config(git_default_config, NULL);
  54                pager = pager_program;
  55        }
  56        if (!pager)
  57                pager = getenv("PAGER");
  58        if (!pager)
  59                pager = DEFAULT_PAGER;
  60        if (!*pager || !strcmp(pager, "cat"))
  61                pager = NULL;
  62
  63        return pager;
  64}
  65
  66void prepare_pager_args(struct child_process *pager_process, const char *pager)
  67{
  68        argv_array_push(&pager_process->args, pager);
  69        pager_process->use_shell = 1;
  70        if (!getenv("LESS"))
  71                argv_array_push(&pager_process->env_array, "LESS=FRX");
  72        if (!getenv("LV"))
  73                argv_array_push(&pager_process->env_array, "LV=-c");
  74}
  75
  76void setup_pager(void)
  77{
  78        const char *pager = git_pager(isatty(1));
  79
  80        if (!pager)
  81                return;
  82
  83        /*
  84         * force computing the width of the terminal before we redirect
  85         * the standard output to the pager.
  86         */
  87        (void) term_columns();
  88
  89        setenv("GIT_PAGER_IN_USE", "true", 1);
  90
  91        /* spawn the pager */
  92        prepare_pager_args(&pager_process, pager);
  93        pager_process.in = -1;
  94        argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
  95        if (start_command(&pager_process))
  96                return;
  97
  98        /* original process continues, but writes to the pipe */
  99        dup2(pager_process.in, 1);
 100        if (isatty(2))
 101                dup2(pager_process.in, 2);
 102        close(pager_process.in);
 103
 104        /* this makes sure that the parent terminates after the pager */
 105        sigchain_push_common(wait_for_pager_signal);
 106        atexit(wait_for_pager_atexit);
 107}
 108
 109int pager_in_use(void)
 110{
 111        const char *env;
 112        env = getenv("GIT_PAGER_IN_USE");
 113        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 114}
 115
 116/*
 117 * Return cached value (if set) or $COLUMNS environment variable (if
 118 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
 119 * and default to 80 if all else fails.
 120 */
 121int term_columns(void)
 122{
 123        static int term_columns_at_startup;
 124
 125        char *col_string;
 126        int n_cols;
 127
 128        if (term_columns_at_startup)
 129                return term_columns_at_startup;
 130
 131        term_columns_at_startup = 80;
 132
 133        col_string = getenv("COLUMNS");
 134        if (col_string && (n_cols = atoi(col_string)) > 0)
 135                term_columns_at_startup = n_cols;
 136#ifdef TIOCGWINSZ
 137        else {
 138                struct winsize ws;
 139                if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
 140                        term_columns_at_startup = ws.ws_col;
 141        }
 142#endif
 143
 144        return term_columns_at_startup;
 145}
 146
 147/*
 148 * How many columns do we need to show this number in decimal?
 149 */
 150int decimal_width(uintmax_t number)
 151{
 152        int width;
 153
 154        for (width = 1; number >= 10; width++)
 155                number /= 10;
 156        return width;
 157}
 158
 159/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
 160int check_pager_config(const char *cmd)
 161{
 162        int want = -1;
 163        struct strbuf key = STRBUF_INIT;
 164        const char *value = NULL;
 165        strbuf_addf(&key, "pager.%s", cmd);
 166        if (git_config_key_is_valid(key.buf) &&
 167            !git_config_get_value(key.buf, &value)) {
 168                int b = git_config_maybe_bool(key.buf, value);
 169                if (b >= 0)
 170                        want = b;
 171                else {
 172                        want = 1;
 173                        pager_program = xstrdup(value);
 174                }
 175        }
 176        strbuf_release(&key);
 177        return want;
 178}