diff options
Diffstat (limited to 'src/journal/cat.c')
| -rw-r--r-- | src/journal/cat.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/src/journal/cat.c b/src/journal/cat.c new file mode 100644 index 0000000..609ddba --- /dev/null +++ b/src/journal/cat.c @@ -0,0 +1,185 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fcntl.h> +#include <getopt.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/stat.h> +#include <unistd.h> + +#include "sd-journal.h" + +#include "alloc-util.h" +#include "build.h" +#include "fd-util.h" +#include "format-util.h" +#include "main-func.h" +#include "parse-argument.h" +#include "parse-util.h" +#include "pretty-print.h" +#include "string-util.h" +#include "syslog-util.h" +#include "terminal-util.h" + +static const char *arg_identifier = NULL; +static int arg_priority = LOG_INFO; +static int arg_stderr_priority = -1; +static bool arg_level_prefix = true; + +static int help(void) { + _cleanup_free_ char *link = NULL; + int r; + + r = terminal_urlify_man("systemd-cat", "1", &link); + if (r < 0) + return log_oom(); + + printf("%s [OPTIONS...] COMMAND ...\n" + "\n%sExecute process with stdout/stderr connected to the journal.%s\n\n" + " -h --help Show this help\n" + " --version Show package version\n" + " -t --identifier=STRING Set syslog identifier\n" + " -p --priority=PRIORITY Set priority value (0..7)\n" + " --stderr-priority=PRIORITY Set priority value (0..7) used for stderr\n" + " --level-prefix=BOOL Control whether level prefix shall be parsed\n" + "\nSee the %s for details.\n", + program_invocation_short_name, + ansi_highlight(), + ansi_normal(), + link); + + return 0; +} + +static int parse_argv(int argc, char *argv[]) { + + enum { + ARG_VERSION = 0x100, + ARG_STDERR_PRIORITY, + ARG_LEVEL_PREFIX + }; + + static const struct option options[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, ARG_VERSION }, + { "identifier", required_argument, NULL, 't' }, + { "priority", required_argument, NULL, 'p' }, + { "stderr-priority", required_argument, NULL, ARG_STDERR_PRIORITY }, + { "level-prefix", required_argument, NULL, ARG_LEVEL_PREFIX }, + {} + }; + + int c, r; + + assert(argc >= 0); + assert(argv); + + /* Resetting to 0 forces the invocation of an internal initialization routine of getopt_long() + * that checks for GNU extensions in optstring ('-' or '+' at the beginning). */ + optind = 0; + while ((c = getopt_long(argc, argv, "+ht:p:", options, NULL)) >= 0) + + switch (c) { + + case 'h': + help(); + return 0; + + case ARG_VERSION: + return version(); + + case 't': + if (isempty(optarg)) + arg_identifier = NULL; + else + arg_identifier = optarg; + break; + + case 'p': + arg_priority = log_level_from_string(optarg); + if (arg_priority < 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Failed to parse priority value."); + break; + + case ARG_STDERR_PRIORITY: + arg_stderr_priority = log_level_from_string(optarg); + if (arg_stderr_priority < 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Failed to parse stderr priority value."); + break; + + case ARG_LEVEL_PREFIX: + r = parse_boolean_argument("--level-prefix=", optarg, &arg_level_prefix); + if (r < 0) + return r; + break; + + case '?': + return -EINVAL; + + default: + assert_not_reached(); + } + + return 1; +} + +static int run(int argc, char *argv[]) { + _cleanup_close_ int outfd = -EBADF, errfd = -EBADF, saved_stderr = -EBADF; + int r; + + log_setup(); + + r = parse_argv(argc, argv); + if (r <= 0) + return r; + + outfd = sd_journal_stream_fd(arg_identifier, arg_priority, arg_level_prefix); + if (outfd < 0) + return log_error_errno(outfd, "Failed to create stream fd: %m"); + + if (arg_stderr_priority >= 0 && arg_stderr_priority != arg_priority) { + errfd = sd_journal_stream_fd(arg_identifier, arg_stderr_priority, arg_level_prefix); + if (errfd < 0) + return log_error_errno(errfd, "Failed to create stream fd: %m"); + } + + saved_stderr = fcntl(STDERR_FILENO, F_DUPFD_CLOEXEC, 3); + + r = rearrange_stdio(STDIN_FILENO, outfd, errfd < 0 ? outfd : errfd); /* Invalidates fd on success + error! */ + TAKE_FD(outfd); + TAKE_FD(errfd); + if (r < 0) + return log_error_errno(r, "Failed to rearrange stdout/stderr: %m"); + + if (argc <= optind) + (void) execl("/bin/cat", "/bin/cat", NULL); + else { + _cleanup_free_ char *s = NULL; + struct stat st; + + if (fstat(STDERR_FILENO, &st) < 0) + return log_error_errno(errno, + "Failed to fstat(%s): %m", + FORMAT_PROC_FD_PATH(STDERR_FILENO)); + + if (asprintf(&s, DEV_FMT ":" INO_FMT, (dev_t)st.st_dev, st.st_ino) < 0) + return log_oom(); + + if (setenv("JOURNAL_STREAM", s, /* overwrite = */ true) < 0) + return log_error_errno(errno, "Failed to set environment variable JOURNAL_STREAM: %m"); + + (void) execvp(argv[optind], argv + optind); + } + r = -errno; + + /* Let's try to restore a working stderr, so we can print the error message */ + if (saved_stderr >= 0) + (void) dup3(saved_stderr, STDERR_FILENO, 0); + + return log_error_errno(r, "Failed to execute process: %m"); +} + +DEFINE_MAIN_FUNCTION(run); |