Bash Listing Files in a Directory and Testing whether Specific Files Exist in Directories: Difference between revisions

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(Created page with "=Internal= * bash =Overview= To list files: local dir=... for f in ${dir}/*; do [[ -f ${f} ]] && echo -n "$(basename ${f}) " done To...")
 
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Line 7: Line 7:
To list files:
To list files:


local dir=...
<syntaxhighlight lang='bash'>
local dir=...


for f in ${dir}/*; do
for f in ${dir}/*; do
  [[ -f ${f} ]] && echo -n "$(basename ${f}) "
  [[ -f ${f} ]] && echo -n "$(basename ${f}) "
  done
done
</syntaxhighlight>


To list directories, replace -f with -d.
To list directories, replace -f with -d.
Note that if ${dir} does not exist, or if it exists and there are no files in that directory, f is resolved to the literal "dirname/*".
Multiple directories:
<syntaxhighlight lang='bash'>
for f in t/master-* t/worker-*; do
    [[ -f ${f} ]] && { rm ${f} && info "deleted ${f}" || warn "failed to delete ${f}"; }
done
</syntaxhighlight>
=Variations=
<font color=darkgray>
'''find''': To further research, it seems the following approach does not work because if there is more than one directory, the first iteration assigns a multi-line to d:
<syntaxhighlight lang='bash'>
for d in $(find ${dir} -name "*-something" -type d); do
  debug "d: ${d}"
  ...
done
</syntaxhighlight>
'''ls''': Same for ls, $(ls ...) produces multi-line output.go
</font>

Revision as of 23:43, 5 December 2019

Internal

Overview

To list files:

local dir=...

for f in ${dir}/*; do
  [[ -f ${f} ]] && echo -n "$(basename ${f}) "
done

To list directories, replace -f with -d.

Note that if ${dir} does not exist, or if it exists and there are no files in that directory, f is resolved to the literal "dirname/*".

Multiple directories:

for f in t/master-* t/worker-*; do
    [[ -f ${f} ]] && { rm ${f} && info "deleted ${f}" || warn "failed to delete ${f}"; }
done

Variations

find: To further research, it seems the following approach does not work because if there is more than one directory, the first iteration assigns a multi-line to d:

for d in $(find ${dir} -name "*-something" -type d); do
  debug "d: ${d}"
  ...
done

ls: Same for ls, $(ls ...) produces multi-line output.go