Does cd . have use?
One of the tutorials I've been following briefly stated that cd . has no use. When trying to replicate issue shown by OP in Symbolic link recursion - what makes it “reset”?, I also tried cd ., which showed the same effect OP described (growing $PWD variable), which can be countered with cd -P.
This makes me wonder, is there any case where one does in fact would want to use cd . ?
cd-command
asked 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
add a comment |
One of the tutorials I've been following briefly stated that cd . has no use. When trying to replicate issue shown by OP in Symbolic link recursion - what makes it “reset”?, I also tried cd ., which showed the same effect OP described (growing $PWD variable), which can be countered with cd -P.
This makes me wonder, is there any case where one does in fact would want to use cd . ?
cd-command
asked 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
add a comment |
One of the tutorials I've been following briefly stated that cd . has no use. When trying to replicate issue shown by OP in Symbolic link recursion - what makes it “reset”?, I also tried cd ., which showed the same effect OP described (growing $PWD variable), which can be countered with cd -P.
This makes me wonder, is there any case where one does in fact would want to use cd . ?
cd-command
asked 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
One of the tutorials I've been following briefly stated that cd . has no use. When trying to replicate issue shown by OP in Symbolic link recursion - what makes it “reset”?, I also tried cd ., which showed the same effect OP described (growing $PWD variable), which can be countered with cd -P.
This makes me wonder, is there any case where one does in fact would want to use cd . ?
cd-command
cd-command
asked 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
asked 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
asked 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
asked 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
asked 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
8,69412355
add a comment |
add a comment |
1 Answer
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The path of directory could have changed since the last executed command and without cd . bash and ksh93 shells will rely on logical working directory described in the linked post in the question; so calling cd . which makes the shell issue getcwd() syscall, will ensure your current path is still valid.
Steps to reproduce in bash:
- in terminal tab issue
mkdir ./dir_no_1; cd ./dir_no_1
- in different terminal tab issue
mv dir_no_1 dir_no_2
- issue in first terminal tab
echo $PWDandpwd. Notice that the directory has been externally renamed, shell's environment has not been updated. - issue
cd .; pwd; echo $PWD. Notice the value will be updated.
ksh93, however, does not update the environment information, so cd . in ksh93 may in fact be useless. In /bin/dash on Ubuntu and other Debian based systems, cd . returns dash: 3: cd: can't cd to . error, however cd -P . works ( unlike in ksh93 ).
answered 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
add a comment |
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1 Answer
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active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
The path of directory could have changed since the last executed command and without cd . bash and ksh93 shells will rely on logical working directory described in the linked post in the question; so calling cd . which makes the shell issue getcwd() syscall, will ensure your current path is still valid.
Steps to reproduce in bash:
- in terminal tab issue
mkdir ./dir_no_1; cd ./dir_no_1
- in different terminal tab issue
mv dir_no_1 dir_no_2
- issue in first terminal tab
echo $PWDandpwd. Notice that the directory has been externally renamed, shell's environment has not been updated. - issue
cd .; pwd; echo $PWD. Notice the value will be updated.
ksh93, however, does not update the environment information, so cd . in ksh93 may in fact be useless. In /bin/dash on Ubuntu and other Debian based systems, cd . returns dash: 3: cd: can't cd to . error, however cd -P . works ( unlike in ksh93 ).
answered 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
add a comment |
The path of directory could have changed since the last executed command and without cd . bash and ksh93 shells will rely on logical working directory described in the linked post in the question; so calling cd . which makes the shell issue getcwd() syscall, will ensure your current path is still valid.
Steps to reproduce in bash:
- in terminal tab issue
mkdir ./dir_no_1; cd ./dir_no_1
- in different terminal tab issue
mv dir_no_1 dir_no_2
- issue in first terminal tab
echo $PWDandpwd. Notice that the directory has been externally renamed, shell's environment has not been updated. - issue
cd .; pwd; echo $PWD. Notice the value will be updated.
ksh93, however, does not update the environment information, so cd . in ksh93 may in fact be useless. In /bin/dash on Ubuntu and other Debian based systems, cd . returns dash: 3: cd: can't cd to . error, however cd -P . works ( unlike in ksh93 ).
answered 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
add a comment |
The path of directory could have changed since the last executed command and without cd . bash and ksh93 shells will rely on logical working directory described in the linked post in the question; so calling cd . which makes the shell issue getcwd() syscall, will ensure your current path is still valid.
Steps to reproduce in bash:
- in terminal tab issue
mkdir ./dir_no_1; cd ./dir_no_1
- in different terminal tab issue
mv dir_no_1 dir_no_2
- issue in first terminal tab
echo $PWDandpwd. Notice that the directory has been externally renamed, shell's environment has not been updated. - issue
cd .; pwd; echo $PWD. Notice the value will be updated.
ksh93, however, does not update the environment information, so cd . in ksh93 may in fact be useless. In /bin/dash on Ubuntu and other Debian based systems, cd . returns dash: 3: cd: can't cd to . error, however cd -P . works ( unlike in ksh93 ).
answered 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
The path of directory could have changed since the last executed command and without cd . bash and ksh93 shells will rely on logical working directory described in the linked post in the question; so calling cd . which makes the shell issue getcwd() syscall, will ensure your current path is still valid.
Steps to reproduce in bash:
- in terminal tab issue
mkdir ./dir_no_1; cd ./dir_no_1
- in different terminal tab issue
mv dir_no_1 dir_no_2
- issue in first terminal tab
echo $PWDandpwd. Notice that the directory has been externally renamed, shell's environment has not been updated. - issue
cd .; pwd; echo $PWD. Notice the value will be updated.
ksh93, however, does not update the environment information, so cd . in ksh93 may in fact be useless. In /bin/dash on Ubuntu and other Debian based systems, cd . returns dash: 3: cd: can't cd to . error, however cd -P . works ( unlike in ksh93 ).
answered 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
answered 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
answered 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
answered 11 mins ago
Sergiy KolodyazhnyySergiy Kolodyazhnyy
8,69412355
8,69412355
add a comment |
add a comment |
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