Andrew's git / gitweb.git /
70159b8858c61f8c5c5577aefcfc2569956c5ddd
   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
   9static struct child_process pager_process = CHILD_PROCESS_INIT;
  10
  11static void wait_for_pager(int in_signal)
  12{
  13        if (!in_signal) {
  14                fflush(stdout);
  15                fflush(stderr);
  16        }
  17        /* signal EOF to pager */
  18        close(1);
  19        close(2);
  20        if (in_signal)
  21                finish_command_in_signal(&pager_process);
  22        else
  23                finish_command(&pager_process);
  24}
  25
  26static void wait_for_pager_atexit(void)
  27{
  28        wait_for_pager(0);
  29}
  30
  31static void wait_for_pager_signal(int signo)
  32{
  33        wait_for_pager(1);
  34        sigchain_pop(signo);
  35        raise(signo);
  36}
  37
  38const char *git_pager(int stdout_is_tty)
  39{
  40        const char *pager;
  41
  42        if (!stdout_is_tty)
  43                return NULL;
  44
  45        pager = getenv("GIT_PAGER");
  46        if (!pager) {
  47                if (!pager_program)
  48                        git_config(git_default_config, NULL);
  49                pager = pager_program;
  50        }
  51        if (!pager)
  52                pager = getenv("PAGER");
  53        if (!pager)
  54                pager = DEFAULT_PAGER;
  55        if (!*pager || !strcmp(pager, "cat"))
  56                pager = NULL;
  57
  58        return pager;
  59}
  60
  61void prepare_pager_args(struct child_process *pager_process, const char *pager)
  62{
  63        argv_array_push(&pager_process->args, pager);
  64        pager_process->use_shell = 1;
  65        if (!getenv("LESS"))
  66                argv_array_push(&pager_process->env_array, "LESS=FRX");
  67        if (!getenv("LV"))
  68                argv_array_push(&pager_process->env_array, "LV=-c");
  69}
  70
  71void setup_pager(void)
  72{
  73        const char *pager = git_pager(isatty(1));
  74
  75        if (!pager)
  76                return;
  77
  78        /*
  79         * force computing the width of the terminal before we redirect
  80         * the standard output to the pager.
  81         */
  82        (void) term_columns();
  83
  84        setenv("GIT_PAGER_IN_USE", "true", 1);
  85
  86        /* spawn the pager */
  87        prepare_pager_args(&pager_process, pager);
  88        pager_process.in = -1;
  89        argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
  90        if (start_command(&pager_process))
  91                return;
  92
  93        /* original process continues, but writes to the pipe */
  94        dup2(pager_process.in, 1);
  95        if (isatty(2))
  96                dup2(pager_process.in, 2);
  97        close(pager_process.in);
  98
  99        /* this makes sure that the parent terminates after the pager */
 100        sigchain_push_common(wait_for_pager_signal);
 101        atexit(wait_for_pager_atexit);
 102}
 103
 104int pager_in_use(void)
 105{
 106        const char *env;
 107        env = getenv("GIT_PAGER_IN_USE");
 108        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 109}
 110
 111/*
 112 * Return cached value (if set) or $COLUMNS environment variable (if
 113 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
 114 * and default to 80 if all else fails.
 115 */
 116int term_columns(void)
 117{
 118        static int term_columns_at_startup;
 119
 120        char *col_string;
 121        int n_cols;
 122
 123        if (term_columns_at_startup)
 124                return term_columns_at_startup;
 125
 126        term_columns_at_startup = 80;
 127
 128        col_string = getenv("COLUMNS");
 129        if (col_string && (n_cols = atoi(col_string)) > 0)
 130                term_columns_at_startup = n_cols;
 131#ifdef TIOCGWINSZ
 132        else {
 133                struct winsize ws;
 134                if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
 135                        term_columns_at_startup = ws.ws_col;
 136        }
 137#endif
 138
 139        return term_columns_at_startup;
 140}
 141
 142/*
 143 * How many columns do we need to show this number in decimal?
 144 */
 145int decimal_width(uintmax_t number)
 146{
 147        int width;
 148
 149        for (width = 1; number >= 10; width++)
 150                number /= 10;
 151        return width;
 152}
 153
 154/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
 155int check_pager_config(const char *cmd)
 156{
 157        int want = -1;
 158        struct strbuf key = STRBUF_INIT;
 159        const char *value = NULL;
 160        strbuf_addf(&key, "pager.%s", cmd);
 161        if (git_config_key_is_valid(key.buf) &&
 162            !git_config_get_value(key.buf, &value)) {
 163                int b = git_config_maybe_bool(key.buf, value);
 164                if (b >= 0)
 165                        want = b;
 166                else {
 167                        want = 1;
 168                        pager_program = xstrdup(value);
 169                }
 170        }
 171        strbuf_release(&key);
 172        return want;
 173}