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
  66static void setup_pager_env(struct argv_array *env)
  67{
  68        const char **argv;
  69        int i;
  70        char *pager_env = xstrdup(PAGER_ENV);
  71        int n = split_cmdline(pager_env, &argv);
  72
  73        if (n < 0)
  74                die("malformed build-time PAGER_ENV: %s",
  75                        split_cmdline_strerror(n));
  76
  77        for (i = 0; i < n; i++) {
  78                char *cp = strchr(argv[i], '=');
  79
  80                if (!cp)
  81                        die("malformed build-time PAGER_ENV");
  82
  83                *cp = '\0';
  84                if (!getenv(argv[i])) {
  85                        *cp = '=';
  86                        argv_array_push(env, argv[i]);
  87                }
  88        }
  89        free(pager_env);
  90        free(argv);
  91}
  92
  93void prepare_pager_args(struct child_process *pager_process, const char *pager)
  94{
  95        argv_array_push(&pager_process->args, pager);
  96        pager_process->use_shell = 1;
  97        setup_pager_env(&pager_process->env_array);
  98}
  99
 100void setup_pager(void)
 101{
 102        const char *pager = git_pager(isatty(1));
 103
 104        if (!pager)
 105                return;
 106
 107        /*
 108         * force computing the width of the terminal before we redirect
 109         * the standard output to the pager.
 110         */
 111        (void) term_columns();
 112
 113        setenv("GIT_PAGER_IN_USE", "true", 1);
 114
 115        /* spawn the pager */
 116        prepare_pager_args(&pager_process, pager);
 117        pager_process.in = -1;
 118        argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
 119        if (start_command(&pager_process))
 120                return;
 121
 122        /* original process continues, but writes to the pipe */
 123        dup2(pager_process.in, 1);
 124        if (isatty(2))
 125                dup2(pager_process.in, 2);
 126        close(pager_process.in);
 127
 128        /* this makes sure that the parent terminates after the pager */
 129        sigchain_push_common(wait_for_pager_signal);
 130        atexit(wait_for_pager_atexit);
 131}
 132
 133int pager_in_use(void)
 134{
 135        const char *env;
 136        env = getenv("GIT_PAGER_IN_USE");
 137        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 138}
 139
 140/*
 141 * Return cached value (if set) or $COLUMNS environment variable (if
 142 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
 143 * and default to 80 if all else fails.
 144 */
 145int term_columns(void)
 146{
 147        static int term_columns_at_startup;
 148
 149        char *col_string;
 150        int n_cols;
 151
 152        if (term_columns_at_startup)
 153                return term_columns_at_startup;
 154
 155        term_columns_at_startup = 80;
 156
 157        col_string = getenv("COLUMNS");
 158        if (col_string && (n_cols = atoi(col_string)) > 0)
 159                term_columns_at_startup = n_cols;
 160#ifdef TIOCGWINSZ
 161        else {
 162                struct winsize ws;
 163                if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
 164                        term_columns_at_startup = ws.ws_col;
 165        }
 166#endif
 167
 168        return term_columns_at_startup;
 169}
 170
 171/*
 172 * How many columns do we need to show this number in decimal?
 173 */
 174int decimal_width(uintmax_t number)
 175{
 176        int width;
 177
 178        for (width = 1; number >= 10; width++)
 179                number /= 10;
 180        return width;
 181}
 182
 183/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
 184int check_pager_config(const char *cmd)
 185{
 186        int want = -1;
 187        struct strbuf key = STRBUF_INIT;
 188        const char *value = NULL;
 189        strbuf_addf(&key, "pager.%s", cmd);
 190        if (git_config_key_is_valid(key.buf) &&
 191            !git_config_get_value(key.buf, &value)) {
 192                int b = git_config_maybe_bool(key.buf, value);
 193                if (b >= 0)
 194                        want = b;
 195                else {
 196                        want = 1;
 197                        pager_program = xstrdup(value);
 198                }
 199        }
 200        strbuf_release(&key);
 201        return want;
 202}