Andreas EricssonSubject: [PATCH] C implementation of the 'git' program.
This patch provides a C implementation of the 'git' program and introduces support for putting the git-* commands in their own directory. It also saves some time on executing git-* commands in a tight loop and it prints the currently available git commands in a nicely formatted list.
The location of the GIT_LIB can be obtained by running
git --lib
which will hopefully give porcelainistas ample time to adapt their heavy-duty loops to use the programs in the library directly if they wish, although that's strictly speaking not really necessary any more.
Some timing values for 10000 invocations of git-var >&/dev/null; git.sh: 24.194s git.c: 9.044s git-var: 7.377s
The git-<tab><tab> behaviour can still be obtained by adding
PATH=$PATH:$(git --lib)
to one's .profile.
Experimental libraries can be used by either setting the environment variable GIT_LIB, or by using
git --lib=/some/experimental/lib
As a nice side-effect, the patch also fixes the problem with make make prefix=/usr install
Signed-off-by: Andreas Ericsson <ae@op5.se>
---
Documentation/git.txt | 6 + Makefile | 24 ++--- git.c | 224 +++++++++++++++++++++++++++++++++++++++++++++++++ git.sh | 76 ----------------- 4 files changed, 239 insertions(+), 91 deletions(-) create mode 100644 git.c delete mode 100755 git.sh
applies-to: 6466c53ae80cddbb581c5fdb2332f9321fade867 b2b97ed9901915dce573516e3a6f10a60bc0c04a
Show changes to 4 files +239 −91
Documentation/git.txt, Makefile, git.c, git.sh
diff --git a/Documentation/git.txt b/Documentation/git.txt index 2f9622f..848d09a 100644 --- a/Documentation/git.txt +++ b/Documentation/git.txt @@ -8,7 +8,7 @@ git - the stupid content tracker SYNOPSIS -------- -'git-<command>' <args> +'git' [--version] [--lib[=GIT_LIB]] [--help] <command> <args> DESCRIPTION ----------- @@ -535,7 +535,9 @@ include::../README[] Author ------ -Written by Linus Torvalds <torvalds@osdl.org> and the git-list <git@vger.kernel.org>. +git's founding father is Linus Torvalds <torvalds@osdl.org>. +The current git nurse is Junio C. Hamano <junkio@cox.net>. +Numerous contributions stem from the git-list <git@vger.kernel.org>. Documentation -------------- diff --git a/Makefile b/Makefile index b202be1..80d865b 100644 --- a/Makefile +++ b/Makefile @@ -59,6 +59,8 @@ ALL_CFLAGS = $(CFLAGS) prefix = $(HOME) bindir = $(prefix)/bin +# XXX set libdir to bindir for now to not break the porcelain +libdir = $(bindir) template_dir = $(prefix)/share/git-core/templates/ GIT_PYTHON_DIR = $(prefix)/share/git-core/python # DESTDIR= @@ -86,7 +88,7 @@ SCRIPT_SH = \ git-prune.sh git-pull.sh git-push.sh git-rebase.sh \ git-repack.sh git-request-pull.sh git-reset.sh \ git-resolve.sh git-revert.sh git-sh-setup.sh git-status.sh \ - git-tag.sh git-verify-tag.sh git-whatchanged.sh git.sh \ + git-tag.sh git-verify-tag.sh git-whatchanged.sh \ git-applymbox.sh git-applypatch.sh git-am.sh \ git-merge.sh git-merge-stupid.sh git-merge-octopus.sh \ git-merge-resolve.sh git-merge-ours.sh git-grep.sh @@ -323,19 +325,13 @@ SCRIPTS = $(patsubst %.sh,%,$(SCRIPT_SH) export prefix TAR INSTALL DESTDIR SHELL_PATH template_dir ### Build rules -all: $(PROGRAMS) $(SCRIPTS) +all: $(PROGRAMS) $(SCRIPTS) git -all: - $(MAKE) -C templates +git: git.c + $(CC) $(CFLAGS) $< -o $@ -DDEFAULT_GIT_LIB='"$(libdir)"' -DGIT_VERSION='"$(GIT_VERSION)"' -git: git.sh Makefile - rm -f $@+ $@ - sed -e '1s|#!.*/sh|#!$(call shq,$(SHELL_PATH))|' \ - -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \ - -e 's/@@X@@/$(X)/g' \ - $(GIT_LIST_TWEAK) <$@.sh >$@+ - chmod +x $@+ - mv $@+ $@ +# Force rebuild so that "make prefix=<something> install" Just Works. +.PHONY: git $(filter-out git,$(patsubst %.sh,%,$(SCRIPT_SH))) : % : %.sh rm -f $@ @@ -420,8 +416,10 @@ check: ### Installation rules install: $(PROGRAMS) $(SCRIPTS) + $(INSTALL) -d -m755 $(call shellquote,$(DESTDIR)$(libdir)) + $(INSTALL) $(PROGRAMS) $(SCRIPTS) $(call shellquote,$(DESTDIR)$(libdir)) $(INSTALL) -d -m755 $(call shellquote,$(DESTDIR)$(bindir)) - $(INSTALL) $(PROGRAMS) $(SCRIPTS) $(call shellquote,$(DESTDIR)$(bindir)) + $(INSTALL) git $(call shellquote,$(DESTDIR)$(bindir)) $(MAKE) -C templates install $(INSTALL) -d -m755 $(call shellquote,$(DESTDIR)$(GIT_PYTHON_DIR)) $(INSTALL) $(PYMODULES) $(call shellquote,$(DESTDIR)$(GIT_PYTHON_DIR)) diff --git a/git.c b/git.c new file mode 100644 index 0000000..8c01723 --- /dev/null +++ b/git.c @@ -0,0 +1,224 @@ +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <limits.h> +#include <stdarg.h> +#include <glob.h> + +#ifndef PATH_MAX +# define PATH_MAX 4096 +#endif + +static const char git_usage[] = + "Usage: git [--version] [--lib[=<GIT_LIB>]] COMMAND [ OPTIONS ]"; + +struct string_list { + size_t len; + char *str; + struct string_list *next; +}; + +/* most gui terms set COLUMNS (although some don't export it) */ +static int columns(void) +{ + char *col_string = getenv("COLUMNS"); + int n_cols = 0; + + if (col_string && (n_cols = atoi(col_string)) > 0) + return n_cols; + + return 80; +} + +static inline void mput_char(char c, unsigned int num) +{ + unsigned int i; + + for(i = 0; i < num; i++) + putchar(c); +} + +static void fmt_print_string_list(struct string_list *list, int longest) +{ + int cols; + int space = longest + 1; /* space between start of string1 and string2 */ + int max_cols = columns() - 1; + + cols = max_cols / space; + + if(cols < 1) { + cols = 1; + space = 0; + } + + while (list) { + int c = cols; + printf(" "); + + for(c = cols; c; c--) { + if (!list) + break; + + printf("%s", list->str); + + if (space && c != 1) + mput_char(' ', space - list->len); + + list = list->next; + } + + putchar('\n'); + } +} + +#ifdef __GNUC__ +static void usage(char *path, const char *fmt, ...) + __attribute__((__format__(__printf__, 2, 3), __noreturn__)); +#endif + +static void usage(char *path, const char *fmt, ...) +{ + struct string_list *list, *tail; + unsigned int longest = 0, i; + glob_t gl; + + list = tail = NULL; + + if (!fmt) + puts(git_usage); + else { + printf("git: "); + va_list ap; + va_start(ap, fmt); + vprintf(fmt, ap); + va_end(ap); + putchar('\n'); + } + + putchar('\n'); + + if (!path) + exit(1); + + if (chdir(path) < 0) { + printf("git: '%s': %s\n", path, strerror(errno)); + exit(1); + } + + i = glob("git-*", 0, NULL, &gl); + if (i) { + switch(i) { + case GLOB_NOSPACE: + puts("Out of memory while glob()'ing commands"); + exit(2); + case GLOB_ABORTED: + printf("'%s': Read error: %s\n", path, strerror(errno)); + exit(2); + case GLOB_NOMATCH: + printf("No git commands available in '%s'.\n", path); + printf("Do you need to specify --lib or set GIT_LIB?\n"); + exit(1); + } + } + + for (i = 0; i < gl.gl_pathc; i++) { + int len = strlen(gl.gl_pathv[i] + 4); + + if(access(gl.gl_pathv[i], X_OK)) + continue; + + if (longest < len) + longest = len; + + if (!tail) + tail = list = malloc(sizeof(struct string_list)); + else { + tail->next = malloc(sizeof(struct string_list)); + tail = tail->next; + } + tail->len = len; + tail->str = gl.gl_pathv[i] + 4; + tail->next = NULL; + } + + printf("git commands available in '%s'\n", path); + printf("----------------------------"); + mput_char('-', strlen(path)); + putchar('\n'); + fmt_print_string_list(list, longest); + + puts("\nman-pages can be reached through 'man git-<COMMAND>'\n"); + + exit(1); +} + +int main(int argc, char **argv, char **envp) +{ + char git_command[PATH_MAX + 1]; + char wd[PATH_MAX + 1]; + char *git_lib = getenv("GIT_LIB"); + int i, len; + + getcwd(wd, PATH_MAX); + + if (!git_lib) + git_lib = DEFAULT_GIT_LIB; + + if (argc == 1) + usage(git_lib, NULL); + + for (i = 1; i < argc; i++) { + char *arg = argv[i]; + + if (strncmp(arg, "--", 2)) + break; + + arg += 2; + + if (!strncmp(arg, "lib", 3)) { + arg += 3; + if (*arg == '=') + git_lib = arg + 1; + else { + puts(git_lib); + exit(0); + } + } + else if (!strcmp(arg, "version")) { + printf("git version %s\n", GIT_VERSION); + exit(0); + } + else if (!strcmp(arg, "help")) + usage(git_lib, NULL); + else + usage(NULL, NULL); + } + + if (i >= argc) + usage(NULL, NULL); + + /* allow relative paths, but run with exact */ + if (chdir(git_lib)) { + printf("git: '%s': %s\n", git_lib, strerror(errno)); + exit (1); + } + + getcwd(git_command, sizeof(git_command)); + chdir(wd); + + len = strlen(git_command); + strncat(&git_command[len], "/git-", sizeof(git_command) - len); + len += 5; + strncat(&git_command[len], argv[i], sizeof(git_command) - len); + + if (access(git_command, X_OK)) + usage(git_lib, "'%s' is not a git-command", argv[i]); + + /* execve() can only ever return if it fails */ + execve(git_command, &argv[i], envp); + printf("Failed to run command '%s': %s\n", git_command, strerror(errno)); + + return 1; +} diff --git a/git.sh b/git.sh deleted file mode 100755 index 94940ae..0000000 --- a/git.sh +++ /dev/null @@ -1,76 +0,0 @@ -#!/bin/sh - -cmd= -path=$(dirname "$0") -case "$#" in -0) ;; -*) cmd="$1" - shift - case "$cmd" in - -v|--v|--ve|--ver|--vers|--versi|--versio|--version) - echo "git version @@GIT_VERSION@@" - exit 0 ;; - esac - - test -x "$path/git-$cmd" && exec "$path/git-$cmd" "$@" - - case '@@X@@' in - '') - ;; - *) - test -x "$path/git-$cmd@@X@@" && - exec "$path/git-$cmd@@X@@" "$@" - ;; - esac - ;; -esac - -echo "Usage: git COMMAND [OPTIONS] [TARGET]" -if [ -n "$cmd" ]; then - echo "git command '$cmd' not found." -fi -echo "git commands are:" - -fmt <<\EOF | sed -e 's/^/ /' -add -apply -archimport -bisect -branch -checkout -cherry -clone -commit -count-objects -cvsimport -diff -fetch -format-patch -fsck-objects -get-tar-commit-id -init-db -log -ls-remote -octopus -pack-objects -parse-remote -patch-id -prune -pull -push -rebase -relink -rename -repack -request-pull -reset -resolve -revert -send-email -shortlog -show-branch -status -tag -verify-tag -whatchanged -EOF --- 0.99.9.GIT
