database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-27 12:41:57 +03:00
Code Activity

pg_upgrade: Fix exec_prog API to be less flaky

Browse Source 
The previous signature made it very easy to pass something other than
the printf-format specifier in the corresponding position, without any
warning from the compiler.

While at it, move some of the escaping, redirecting and quoting
responsibilities from the callers into exec_prog() itself.  This makes
the callsites cleaner.
This commit is contained in:
Alvaro Herrera
2012-08-27 14:21:09 -04:00
parent 34c02044ed
commit 088c065ce8
6 changed files with 96 additions and 113 deletions
Download Patch File Download Diff File Expand all files Collapse all files

80
contrib/pg_upgrade/exec.c
View File

@ -26,77 +26,81 @@ static int win32_check_directory_write_permissions(void);
/*
* exec_prog()
* Execute an external program with stdout/stderr redirected, and report
* errors
*
* Formats a command from the given argument list and executes that
* command. If the command executes, exec_prog() returns 1 otherwise
* exec_prog() logs an error message and returns 0. Either way, the command
* line to be executed is saved to the specified log file.
* Formats a command from the given argument list, logs it to the log file,
* and attempts to execute that command. If the command executes
* successfully, exec_prog() returns true.
*
* If throw_error is TRUE, this function will throw a PG_FATAL error
* instead of returning should an error occur. The command it appended
* to log_file; opt_log_file is used in error messages.
* If the command fails, an error message is saved to the specified log_file.
* If throw_error is true, this raises a PG_FATAL error and pg_upgrade
* terminates; otherwise it is just reported as PG_REPORT and exec_prog()
* returns false.
*/
int
exec_prog(bool throw_error, bool is_priv, const char *log_file,
const char *opt_log_file, const char *fmt,...)
bool
exec_prog(const char *log_file, const char *opt_log_file,
bool throw_error, const char *fmt,...)
{
va_list args;
int result;
int retval;
char cmd[MAXPGPATH];
int written;
#define MAXCMDLEN (2 * MAXPGPATH)
char cmd[MAXCMDLEN];
mode_t old_umask = 0;
FILE *log;
va_list ap;
if (is_priv)
old_umask = umask(S_IRWXG | S_IRWXO);
old_umask = umask(S_IRWXG | S_IRWXO);
va_start(args, fmt);
vsnprintf(cmd, MAXPGPATH, fmt, args);
va_end(args);
written = strlcpy(cmd, SYSTEMQUOTE, strlen(SYSTEMQUOTE));
va_start(ap, fmt);
written += vsnprintf(cmd + written, MAXCMDLEN - written, fmt, ap);
va_end(ap);
if (written >= MAXCMDLEN)
pg_log(PG_FATAL, "command too long\n");
written += snprintf(cmd + written, MAXCMDLEN - written,
" >> \"%s\" 2>&1" SYSTEMQUOTE, log_file);
if (written >= MAXCMDLEN)
pg_log(PG_FATAL, "command too long\n");
if ((log = fopen_priv(log_file, "a+")) == NULL)
pg_log(PG_FATAL, "cannot write to log file %s\n", log_file);
pg_log(PG_VERBOSE, "%s\n", cmd);
fprintf(log, "command: %s\n", cmd);
/*
* In Windows, we must close then reopen the log file so the file is
* not open while the command is running, or we get a share violation.
* In Windows, we must close the log file at this point so the file is not
* open while the command is running, or we get a share violation.
*/
fclose(log);
result = system(cmd);
if (is_priv)
umask(old_umask);
umask(old_umask);
if (result != 0)
{
char opt_string[MAXPGPATH];
/* Create string for optional second log file */
if (opt_log_file)
snprintf(opt_string, sizeof(opt_string), " or \"%s\"", opt_log_file);
else
opt_string[0] = '\0';
report_status(PG_REPORT, "*failure*");
fflush(stdout);
pg_log(PG_VERBOSE, "There were problems executing \"%s\"\n", cmd);
pg_log(throw_error ? PG_FATAL : PG_REPORT,
"Consult the last few lines of \"%s\"%s for\n"
"the probable cause of the failure.\n",
log_file, opt_string);
retval = 1;
if (opt_log_file)
pg_log(throw_error ? PG_FATAL : PG_REPORT,
"Consult the last few lines of \"%s\" or \"%s\" for\n"
"the probable cause of the failure.\n",
log_file, opt_log_file);
else
pg_log(throw_error ? PG_FATAL : PG_REPORT,
"Consult the last few lines of \"%s\" for\n"
"the probable cause of the failure.\n",
log_file);
}
else
retval = 0;
if ((log = fopen_priv(log_file, "a+")) == NULL)
pg_log(PG_FATAL, "cannot write to log file %s\n", log_file);
fprintf(log, "\n\n");
fclose(log);
return retval;
return result == 0;
}