From 354826ecbd4c97d6eb469b3cb8444d37cf44feab Mon Sep 17 00:00:00 2001 From: Charles McGarvey Date: Fri, 8 Mar 2013 10:42:01 -0700 Subject: [PATCH] initial commit --- Makefile | 13 +++++ githead.c | 166 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 179 insertions(+) create mode 100644 Makefile create mode 100644 githead.c diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..660931f --- /dev/null +++ b/Makefile @@ -0,0 +1,13 @@ + +PROG= githead + +all: githead + +githead: githead.c + $(CC) -Os -pipe -o $@ $< + +#BINDIR= /usr/local/bin +#MANDIR= /usr/local/man + +#.include + diff --git a/githead.c b/githead.c new file mode 100644 index 0000000..e258a5b --- /dev/null +++ b/githead.c @@ -0,0 +1,166 @@ + +/* + * Get the name of the current git branch (pointed to by HEAD) and print it + * out, color-coded to show if any working files are dirty. This would + * ideally be implemented as a shell script, but I wrote it in C because it + * needs to be fast! And we all know C is fast, amiright? + * + * Also reads in regular expressions (one per line) matching paths that + * should be ignored. Each regex is matched against the top-level + * directory path of the repository. If it matches, nothing is printed. + * It is a good idea to ignore repositories on slow (remote) disks. + * + * Example usage (bash): + * PS1='\u@\h \w$(githead <~/.nogitprompt) $ ' + * + * Written 04 June 2012 by Charles McGarvey. + */ + +const char* ansi_codes = "0;36"; +const char* ansi_codes_dirty = "0;31"; + +#include +#include +#include +#include +#include +#include + +#include +#include + +int main(int argc, char* argv[]) +{ + char buf[4096]; + + char* branch = NULL; + int dirty = 0; + + fclose(stderr); // usually do not want any extra junk printed + + int p[2]; + if (pipe(p) == -1) { + fprintf(stderr, "pipe failed: %s\n", strerror(errno)); + return 1; + } + + pid_t pid1 = fork(); + if (pid1 == -1) { + fprintf(stderr, "fork failed: %s\n", strerror(errno)); + return 1; + } + if (pid1 == 0) { + char* args[] = {"git", "rev-parse", "--show-toplevel", NULL}; + if (dup2(p[1], 1) == -1) { + fprintf(stderr, "dup2 failed: %s\n", strerror(errno)); + } + execvp(args[0], args); + return 0; + } + + close(p[1]); + + int status; + while (waitpid(pid1, &status, 0) < 0) { + if (errno != EINTR) { + fprintf(stderr, "waitpid failed: %s\n", strerror(errno)); + return 1; + } + } + if (WEXITSTATUS(status) == 0) { + ssize_t bytes = read(p[0], buf, sizeof(buf)); + if (bytes < 0) { + fprintf(stderr, "read failed: %s\n", strerror(errno)); + return 1; + } + buf[bytes-1] = '\0'; + + char regbuf[4096]; + while (gets(regbuf)) { + char errbuf[4096]; + regex_t re; + int err = regcomp(&re, regbuf, REG_EXTENDED | REG_ICASE | REG_NOSUB); + if (err != 0) { + regerror(err, &re, errbuf, sizeof(errbuf)); + fprintf(stderr, "regcomp failed: %s\n", errbuf); + continue; + } + if (regexec(&re, buf, 0, NULL, 0) == 0) { + return 0; + } + regfree(&re); + } + } + else { + fprintf(stderr, "git failed; bailing out...\n"); + return 1; + } + + pid_t pid2 = fork(); + if (pid2 == -1) { + fprintf(stderr, "fork failed: %s\n", strerror(errno)); + return 1; + } + if (pid2 == 0) { + char* args[] = {"git", "diff", "--no-ext-diff", "--quiet", "--exit-code", NULL}; + execvp(args[0], args); + return 0; + } + + if (pipe(p) == -1) { + fprintf(stderr, "pipe failed: %s\n", strerror(errno)); + return 1; + } + + pid_t pid3 = fork(); + if (pid3 == -1) { + fprintf(stderr, "fork failed: %s\n", strerror(errno)); + return 1; + } + if (pid3 == 0) { + char* args[] = {"git", "symbolic-ref", "HEAD", NULL}; + if (dup2(p[1], 1) == -1) { + fprintf(stderr, "dup2 failed: %s\n", strerror(errno)); + } + execvp(args[0], args); + return 1; + } + + close(p[1]); + + while (waitpid(pid3, &status, 0) < 0) { + if (errno != EINTR) { + fprintf(stderr, "waitpid failed: %s\n", strerror(errno)); + return 1; + } + } + if (WEXITSTATUS(status) == 0) { + ssize_t bytes = read(p[0], buf, sizeof(buf)); + if (bytes < 0) { + fprintf(stderr, "read failed: %s\n", strerror(errno)); + return 1; + } + buf[bytes-1] = '\0'; + branch = buf + 11; + } + + while (waitpid(pid2, &status, 0) < 0) { + if (errno != EINTR) { + fprintf(stderr, "waitpid failed: %s\n", strerror(errno)); + return 1; + } + } + dirty = (WEXITSTATUS(status) != 0); + + if (branch) { + if (dirty) { + printf("\033[%sm[%s]\033[0m", ansi_codes_dirty, branch); + } + else { + printf("\033[%sm[%s]\033[0m", ansi_codes, branch); + } + } + + return 0; +} + -- 2.43.0