--A function called setproctitle
is available on some systems
--Linux does not have setproctitle
by default. It is troublesome because there is no choice but to rewrite ʻargv [0] --If you write a command name longer than the original, it will destroy the area with environment variables after ʻargv [1]
, so you need to copy it to another location in advance.
--util-linux has a setproctitle
implementation for Linux, so you can easily copy and paste this
――However, please note that it is GPL.
Postscript: When I searched for it, redis also had an implementation. Redis is BSD licensed.
test.c
/*
* set process title for ps (from sendmail)
*
* Clobbers argv of our main procedure so ps(1) will display the title.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
//#include "setproctitle.h"
#ifndef SPT_BUFSIZE
# define SPT_BUFSIZE 2048
#endif
extern char **environ;
static char **argv0;
static int argv_lth;
void initproctitle (int argc, char **argv)
{
int i;
char **envp = environ;
/*
* Move the environment so we can reuse the memory.
* (Code borrowed from sendmail.)
* WARNING: ugly assumptions on memory layout here;
* if this ever causes problems, #undef DO_PS_FIDDLING
*/
for (i = 0; envp[i] != NULL; i++)
continue;
environ = malloc(sizeof(char *) * (i + 1));
if (environ == NULL)
return;
for (i = 0; envp[i] != NULL; i++)
if ((environ[i] = strdup(envp[i])) == NULL)
return;
environ[i] = NULL;
argv0 = argv;
if (i > 0)
argv_lth = envp[i-1] + strlen(envp[i-1]) - argv0[0];
else
argv_lth = argv0[argc-1] + strlen(argv0[argc-1]) - argv0[0];
}
void setproctitle (const char *prog, const char *txt)
{
int i;
char buf[SPT_BUFSIZE];
if (!argv0)
return;
if (strlen(prog) + strlen(txt) + 5 > SPT_BUFSIZE)
return;
sprintf(buf, "%s -- %s", prog, txt);
i = strlen(buf);
if (i > argv_lth - 2) {
i = argv_lth - 2;
buf[i] = '\0';
}
memset(argv0[0], '\0', argv_lth); /* clear the memory area */
strcpy(argv0[0], buf);
argv0[1] = NULL;
}
//Main function for testing
int main(int argc, char* argv[])
{
initproctitle(argc, argv);
setproctitle("hoge", "AIUEO");
printf("Hello my pid = %d\n", getpid());
sleep(10);
return 0;
}
reference:
postgres ps_status.c Command name change is realized by various methods for each platform.
/*
* Alternative ways of updating ps display:
*
* PS_USE_SETPROCTITLE
* use the function setproctitle(const char *, ...)
* (newer BSD systems)
* PS_USE_PSTAT
* use the pstat(PSTAT_SETCMD, )
* (HPUX)
* PS_USE_PS_STRINGS
* assign PS_STRINGS->ps_argvstr = "string"
* (some BSD systems)
* PS_USE_CHANGE_ARGV
* assign argv[0] = "string"
* (some other BSD systems)
* PS_USE_CLOBBER_ARGV
* write over the argv and environment area
* (Linux and most SysV-like systems)
* PS_USE_WIN32
* push the string out as the name of a Windows event
* PS_USE_NONE
* don't update ps display
* (This is the default, as it is safest.)
*/
Recommended Posts