04-10-2010
What happens when you run the ls command on a directory you have permissions to see?
You see all of the files. You see files that are locked, too. This is because ls is looking at file metadata, not the data in the file itself. So it does not open the file, you can think of it as opening the directory instead.
stat() works the same way, it works against file metadata, so it does not matter if another process has the file locked, stat() will work anyway. When you stat a file you are checking it's existence.
More to the point:access() is the system call (unistd.h> that you should use to check file existence and your permissions to it.
Is this what you are asking?
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
I need to write a function that will work in sh/ksh shell that will test to see if a file has already been opened for writting by another user
has anyone written something like this? (3 Replies)
Discussion started by: johnsonbryce
3 Replies
2. Programming
How should I use errno in a c program and what info does it have .
I am working with directories and files.
So can any one tell me How to access errno?I am using the stat() function on \etc directory and I am alble to access only the half of the directories.I am not able to access other half and... (6 Replies)
Discussion started by: vijlak
6 Replies
3. Programming
From reading various articles on the net, I know stat() is used on files to get things like permissions, sizes etc... As a folder is a special type of file in Unix, I assumed that stat() could work on it as well as any general file.
However, from running my program, perror() reported that the... (3 Replies)
Discussion started by: JamesGoh
3 Replies
4. UNIX and Linux Applications
To begin:
I use Linux
The Problem:
I need bcp functionality for scripts. Perl modules, such as Sybase:xfer, require ctlib which comes with Sybase Open Client. Talking with Sybase sales
reps is an exercise in futility and hate. They know absolutely nothing about their own products and will... (0 Replies)
Discussion started by: Bubnoff
0 Replies
5. Programming
Hello All,
i am porting my application from SunSolaris to Linux (RHEL4).
When i compile my c/c++ code i am getting the following errors.
1. catastrophic error: could not open source file "sys/elf_386.h"
#include <sys/elf_386.h>
2. catastrophic error: could not open source file... (2 Replies)
Discussion started by: tsaravanan
2 Replies
6. Shell Programming and Scripting
Help Please perl Gurus,
I am trying to add ungrouped passengers in a group and I creating a script however it fails on first step only I tried all the options it returns following error.
syntax error at junki line 4, near "open "
Execution of junki aborted due to compilation errors. ... (2 Replies)
Discussion started by: dynamax
2 Replies
7. Shell Programming and Scripting
Die to what all operations, the "Modify" and "Change" values of stat output changes for a file.
I found, during editing a file, Change and Modify alters. When chmod'ing Change alters, while Modify doesnot alters. Is there more situations where these changes? (1 Reply)
Discussion started by: anil510
1 Replies
8. Programming
I am opening a text file using open() system call in O_RDONLY mode.
open() returns me a valid handler but also sets errno to 13 i.e. EACCES(Permission denied).
Question is when open() is returning a valid handler then why does it sets the errno?
Should not errno be set only in case of error... (10 Replies)
Discussion started by: rupeshkp728
10 Replies
9. Shell Programming and Scripting
Hello all, just a quick little part of code i'm writing to check if the file i'm writing too in my automatic process is not being written too manually.
#!/bin/bash
FUSER=$(/sbin/fuser -s /toto.tmp >/dev/null 2>&1)
LSOF=$(/usr/sbin/lsof | grep -q "toto.tmp")
PGREP=$(pgrep -f "toto.tmp" >... (6 Replies)
Discussion started by: maverick72
6 Replies
10. Programming
(Apologies for any typos.)
OSX 10.12.3 AND Windows 10.
This is for the serious Python experts on at least 3.5.x and above...
In script format sys.stdout.write() AND sys.stderr.write() seems to work correctly.
Have I found a serious bug in the interactive sys.stdout.write() AND... (2 Replies)
Discussion started by: wisecracker
2 Replies
LEARN ABOUT CENTOS
tcl_stat
Tcl_Access(3) Tcl Library Procedures Tcl_Access(3)
__________________________________________________________________________________________________________________________________________________
NAME
Tcl_Access, Tcl_Stat - check file permissions and other attributes
SYNOPSIS
#include <tcl.h>
int
Tcl_Access(path, mode)
int
Tcl_Stat(path, statPtr)
ARGUMENTS
char *path (in) Native name of the file to check the attributes of.
int mode (in) Mask consisting of one or more of R_OK, W_OK, X_OK and F_OK. R_OK, W_OK and X_OK request checking
whether the file exists and has read, write and execute permissions, respectively. F_OK just
requests checking for the existence of the file.
struct stat *statPtr (out) The structure that contains the result.
_________________________________________________________________
DESCRIPTION
As of Tcl 8.4, the object-based APIs Tcl_FSAccess and Tcl_FSStat should be used in preference to Tcl_Access and Tcl_Stat, wherever possi-
ble.
There are two reasons for calling Tcl_Access and Tcl_Stat rather than calling system level functions access and stat directly. First, the
Windows implementation of both functions fixes some bugs in the system level calls. Second, both Tcl_Access and Tcl_Stat (as well as
Tcl_OpenFileChannelProc) hook into a linked list of functions. This allows the possibility to reroute file access to alternative media or
access methods.
Tcl_Access checks whether the process would be allowed to read, write or test for existence of the file (or other file system object) whose
name is pathname. If pathname is a symbolic link on Unix, then permissions of the file referred by this symbolic link are tested.
On success (all requested permissions granted), zero is returned. On error (at least one bit in mode asked for a permission that is
denied, or some other error occurred), -1 is returned.
Tcl_Stat fills the stat structure statPtr with information about the specified file. You do not need any access rights to the file to get
this information but you need search rights to all directories named in the path leading to the file. The stat structure includes info
regarding device, inode (always 0 on Windows), privilege mode, nlink (always 1 on Windows), user id (always 0 on Windows), group id (always
0 on Windows), rdev (same as device on Windows), size, last access time, last modification time, and creation time.
If path exists, Tcl_Stat returns 0 and the stat structure is filled with data. Otherwise, -1 is returned, and no stat info is given.
KEYWORDS
stat, access
Tcl 8.1 Tcl_Access(3)