Andrew's git - gitweb.git/blob

5dbcc5ace395b0fb5d2fec09e8d53c7f1bce3fb2
   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(void)
  17{
  18        fflush(stdout);
  19        fflush(stderr);
  20        /* signal EOF to pager */
  21        close(1);
  22        close(2);
  23        finish_command(&pager_process);
  24}
  25
  26static void wait_for_pager_signal(int signo)
  27{
  28        wait_for_pager();
  29        sigchain_pop(signo);
  30        raise(signo);
  31}
  32
  33const char *git_pager(int stdout_is_tty)
  34{
  35        const char *pager;
  36
  37        if (!stdout_is_tty)
  38                return NULL;
  39
  40        pager = getenv("GIT_PAGER");
  41        if (!pager) {
  42                if (!pager_program)
  43                        git_config(git_default_config, NULL);
  44                pager = pager_program;
  45        }
  46        if (!pager)
  47                pager = getenv("PAGER");
  48        if (!pager)
  49                pager = DEFAULT_PAGER;
  50        if (!*pager || !strcmp(pager, "cat"))
  51                pager = NULL;
  52
  53        return pager;
  54}
  55
  56void setup_pager(void)
  57{
  58        const char *pager = git_pager(isatty(1));
  59
  60        if (!pager)
  61                return;
  62
  63        /*
  64         * force computing the width of the terminal before we redirect
  65         * the standard output to the pager.
  66         */
  67        (void) term_columns();
  68
  69        setenv("GIT_PAGER_IN_USE", "true", 1);
  70
  71        /* spawn the pager */
  72        argv_array_push(&pager_process.args, pager);
  73        pager_process.use_shell = 1;
  74        pager_process.in = -1;
  75        if (!getenv("LESS"))
  76                argv_array_push(&pager_process.env_array, "LESS=FRX");
  77        if (!getenv("LV"))
  78                argv_array_push(&pager_process.env_array, "LV=-c");
  79        argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
  80        if (start_command(&pager_process))
  81                return;
  82
  83        /* original process continues, but writes to the pipe */
  84        dup2(pager_process.in, 1);
  85        if (isatty(2))
  86                dup2(pager_process.in, 2);
  87        close(pager_process.in);
  88
  89        /* this makes sure that the parent terminates after the pager */
  90        sigchain_push_common(wait_for_pager_signal);
  91        atexit(wait_for_pager);
  92}
  93
  94int pager_in_use(void)
  95{
  96        const char *env;
  97        env = getenv("GIT_PAGER_IN_USE");
  98        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
  99}
 100
 101/*
 102 * Return cached value (if set) or $COLUMNS environment variable (if
 103 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
 104 * and default to 80 if all else fails.
 105 */
 106int term_columns(void)
 107{
 108        static int term_columns_at_startup;
 109
 110        char *col_string;
 111        int n_cols;
 112
 113        if (term_columns_at_startup)
 114                return term_columns_at_startup;
 115
 116        term_columns_at_startup = 80;
 117
 118        col_string = getenv("COLUMNS");
 119        if (col_string && (n_cols = atoi(col_string)) > 0)
 120                term_columns_at_startup = n_cols;
 121#ifdef TIOCGWINSZ
 122        else {
 123                struct winsize ws;
 124                if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
 125                        term_columns_at_startup = ws.ws_col;
 126        }
 127#endif
 128
 129        return term_columns_at_startup;
 130}
 131
 132/*
 133 * How many columns do we need to show this number in decimal?
 134 */
 135int decimal_width(uintmax_t number)
 136{
 137        int width;
 138
 139        for (width = 1; number >= 10; width++)
 140                number /= 10;
 141        return width;
 142}
 143
 144/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
 145int check_pager_config(const char *cmd)
 146{
 147        int want = -1;
 148        struct strbuf key = STRBUF_INIT;
 149        const char *value = NULL;
 150        strbuf_addf(&key, "pager.%s", cmd);
 151        if (!git_config_get_value(key.buf, &value)) {
 152                int b = git_config_maybe_bool(key.buf, value);
 153                if (b >= 0)
 154                        want = b;
 155                else {
 156                        want = 1;
 157                        pager_program = xstrdup(value);
 158                }
 159        }
 160        strbuf_release(&key);
 161        return want;
 162}