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ARSC HPC Users' Newsletter "Quick-Tip" Index
Symbols
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Z
Symbols
- .netrc file , auto-initialize ftp sessions and define ftp macros :
273
- /dev/stdin , accessing stdin as a file :
338
- [ , shell syntax for conditional tests, "/usr/bin/[" versus "/usr/bin/test" versus "[[" :
348
A
- aliases , reader favorites :
146
290
363
- using within scripts :
342
- apportioning K tasks among M PEs :
132
- ar , running ar command on 32 and 64 bit libraries on IBM systems:
333
- using ar or ld to combine .o files and reduce over-sized argument string :
300
- argument list too long , when the shell can't handle wildcard expansion :
216
300
- assign command , translating unformatted files :
219
- automobile engine heater , unplugging :
156
- awk , examples :
272
316
337
356
370
375
- extracting fields from ls output :
356
B
- babel , connecting C/C++ to python :
344
- base conversion , converting numbers between bases in Unix :
282
- basename/dirname commands , return file name or directory path from a path/filename string :
268
- bash , command completion in bash :
353
- extracting the extension from a filename using pattern matching operators :
347
- batch , submitting batch jobs in IRIX :
249
- batch remove , using Unix commands :
179
- bc , evaluating math expressions found in a text file :
285
- bears , defense against :
197
- BLACS , global reductions with BLACS, coding from communication primitives :
351
- blankets on your car , warming your car when it's cold out :
334
- blind directories , safer file sharing :
191
- book review , scientific books :
320
- bucket sort , faster than quicksort :
141
C
- C , C vs Fortran -- default array indexing :
154
155
- calling C from Fortran -- portable interface :
260
- comment blocks for documentation systems :
367
- commenting out commented code, or, how to nest "comments" :
339
- finding path of an executable :
183
- linking gridinfo, gridinit, and FFT libraries with C/C++ code :
233
- path to executable :
183
- pointer reference :
159
- preprocessor directives with make :
326
- pretty-printer :
295
- programming style question, how would you choose the minimum:
264
- question-mark colon construct :
127
- retaining the precision of output doubles using format specifiers :
361
- trapping floating point errors using gcc feenableexcept :
376
- viewing arrays in totalview :
145
- C++ , confusion between "cpp" and "CC" commands :
279
- copying values from a C style array to a STL vector :
350
- linking to C libraries :
308
- using the STL vector assign member function :
350
- using the STL vector reserve member function :
350
- using the stringstream class :
373
- C/C++ , calling from python:
344
349
- carpal tunnel syndrome , avoiding :
113
- Catch-22 :
257
- CDPATH , jumping between directories :
123
- chgrp :
192
- chmod , changing entire path to a selected file, but not recursively :
220
- chmod -R go+rX ; intelligently add execute bit :
147
- chmod 1770 ; sticky bit :
109
- g=x ~ ; blind home directory :
191
- group/world executable directories put at risk all files within :
298
- Co-Array Fortran , array bounds :
154
- code-blindness , cures :
271
- col , -bx ; converting man pages :
118
- Collectives , collective nouns for supercomputer related terminology :
384
- comm , using the comm command to compare files :
362
- commas , reformatting long number strings with comma separators :
329
- Compiler options , -g :
166
- -O3,aggress :
166
- from the executable file, determine what compiler flags were used :
368
- compilers , determining version :
149
- core files , determinine origin of :
200
- limiting size :
121
- cp , -i :
187
- -p ; copying modification time along with the file :
231
- --parents; preserving parent directories (GNU cp) :
377
- cpu , UNICOS /etc/cpu command for control over caching :
209
- Cray Fortran , -Oinlinefrom :
207
- performance comparison of DO-IF vs WHERE:
205
- (/ ... /) syntax ; array constructor :
157
- -eI ; implicit none :
129
- -F ; macro expansion :
174
- -Rb ; array bounds checking :
129
- -rx ; report on variable usage and cross-references :
221
- -s cf77types ; type compatibility with Fortran 77:
174
- -static :
202
- -V ; version :
149
- ALLOCATE statement ; testing for success:
135
- Directive for unwinding loops :
292
- csh , file name completion :
176
- redirecting stderr and stdout :
223
- csh/tcsh , extracting the extension from a filename using variable modifiers :
347
- cURL , command-line retrieval of web pages :
311
- cut , extracting columns of data from text files :
272
337
356
- CVS , alternative to diff :
313
- version control and software maintenance :
278
D
- date stamp, Creating file versions with a date stamp :
310
- dc , desktop calculator :
167
- debugging , finding problem in one of many source files :
275
- deleting ^M characters in batch :
139
287
- deleting the file "-i" :
102
- development environments , reader favorites :
341
- diamond as conductor :
120
- diff , "modern" alternatives to diff (tkdiff, ediff, vimdiff, etc...) :
313
- -D :
124
- comparing a file to stdin :
338
- comparing a remote file to a local file :
338
- ndiff, numerical differences allowed and handled intelligently :
378
- dirname/basename commands , returns directory path or file name from a path/filename string :
268
- DISPLAY environment variable , Incorrect setting causes console session failure :
243
- DMF , File compression and affect on DMF migration :
188
- How to dmput files owned by other members of a group :
222
- dmget , most efficient use :
162
- dotfiles , maintaining consistent dotfiles across multiple systems :
312
- Doxygen , For code documentation :
367
- du , -m ; include Cray DMF migrated files :
164
- -sk ; excludes Cray DMF migrated files, under-estimates size of tar file :
267
- -sk ; totaled disk usage in KBs :
164
E
- e-mail , sending automatic vacation messages :
143
- e-mail from NQS :
138
- echo , for shell preview of wild-card expansion :
256
- editors , favorite development environments :
341
- using text editors to copy/paste rectangular blocks :
272
- egrep , advanced filtering examples :
161
168
337
- emacs , diff-like features :
313
- getting colors to work on any platforms :
297
- tramp to access remote files :
314
- env , /usr/bin/env searches PATH for binary :
372
- environment variables , appending to $PATH, $LM_LICENSE_FILE, etc. :
245
- available to running NQS jobs :
198
- testing if set :
319
- escapes , controlling the interpretation of regular expressions :
280
- ex , single command line "ex" command prepends file A to file B :
302
- expand command , replacing tabs with spaces :
203
- expect , an expect script for ftp initialization :
273
- explain , Cray's "explain" command prints details on many warnings/errors :
293
- expr , differences :
237
- using regular expression to extract a substring :
347
- eye strain , reducing :
106
F
- FFT , linking gridinfo, gridinit, and FFT libraries with C/C++ code :
233
- file command :
112
200
332
- files , access time :
178
- batch editing in place :
126
- compression and its affect on DMF migration :
188
- determining source or type of :
112
- generating unique file names in C/C++/Fortran programs :
229
- sharing with your group without compromising home directory :
191
- find , -exec, using with chmod and -type :
332
- -exec, using with grep :
283
- -exec, using with tar :
331
- -mmin, to find recently modified files (GNU find) :
346
- -mtime to find recently modified files :
346
- -prune ; prevent descending into subdirectory :
181
187
- -size ; finding large files to help stay under quota :
259
- -type m ; finding migrated files :
162
- examples :
147
187
230
283
331
332
357
- preserving files which match a wildcard expression, deleting the rest :
301
- removing core and mppcore files :
107
- Fortran , calling C from Fortran -- portable interface :
260
- CYCLE and EXIT :
248
249
- DO loop iterator exit value, formula for computing :
325
- f90 type inconsistency :
174
- Fortran 90 generic functions :
215
- Fortran 90 INTEGER constants:
215
- Fortran 90 MODULE replaces Fortran 77 COMMON :
199
- Fortran 90 OPTIONAL subroutine args and effect on inlining :
208
- Fortran vs C -- default array indexing :
154
155
- free vs fixed format discussion :
261
- header and include files :
171
- intrinsic functions :
158
- LOG10 vs ALOG10 :
158
- NAMELIST :
213
- OPEN (RECL=1024) :
144
- pretty-printer :
295
- RESHAPE :
228
- trapping floating point errors using gcc feenableexcept :
376
- unformatted files and porting them :
219
- using arbitrary array bounds :
154
155
- WRITE :
144
- WRITE with implied DO incompatible with read with explicit DO :
284
- ftp , automating ftp sessions with batch scripts and initialization macdef macros :
273
- how to "more" remote and local files :
105
- mget/mput a batch of files without prompting :
277
G
- grep , -- ; signifies end of options :
226
- -l ; listing file names :
103
- -o ; Show only the part of a matching line that matches the pattern :
358
- -v ; excluding grep itself from ps output :
224
- list files not containing certain text, using find -exec :
230
- list lines before search pattern :
345
- listing file names even when only one file searched :
283
- searching for multi-line patterns :
371
- grmview , -deq ; determining memory usage at runtime :
134
- -l :
134
- group , group/world executable directories put at risk all files within :
298
- what determines group ownership of a new file :
192
- gzip , Determining if a zipped file is okay without unzipping it :
321
H
- Haskell , examples :
375
- hexidecimal , converting decimal to hex and back in Unix :
282
- hidden characters in file names :
180
I
- ImageMagick for postscript to png image conversion :
374
- implicit none :
129
- adding implicit none and explicit declarations to legacy codes :
221
- Initializing program parameters , avoiding recompilation :
213
- inlining , impeded by Fortran 90 OPTIONAL arguments and one workaround :
208
- inlinefrom required by Cray Fortran if source in separate files :
207
J
- ja , job accounting command :
190
K
- kdestroy , removing Kerberos tickets :
288
- kerberos , kerberos skew too great :
189
- next token mode :
169
- keyboard keys , "enlarging" a too-small key on the keyboard by remapping it :
352
- kill , aborting MPP jobs :
125
- krcp , copying directories recursively :
343
- ksh , "_" environment variable :
183
- CDPATH environment variable :
123
- file name completion :
176
- redirecting stderr and stdout :
223
- history file environment variable, HISTFILE :
317
- integer keyword :
354
- loops in ksh :
354
370
- prompt, favorite settings for your shell prompt :
349
- PS1, favorite settings for your shell prompt :
349
- typeset declaration :
385
L
- ld , using ld or ar to combine .o files and reduce over-sized argument string :
300
- libraries , determining which used :
168
- show which shared library each symbol in an executable is provided by :
383
- limit , limit -d dlim ; limiting size of core files :
121
- setting maximum stack frame size when your code won't compile :
202
- listserver , problems unsubscribing :
218
- llsubmit , starting batch job in directory from which it was submitted :
289
- ln , -s ; preventing core file creation :
114
- Loadleveler , getting number of nodes and procs :
316
- ls * ; listing two subdirectory levels :
128
- ls , -b ; octal codes for nongraphic characters :
180
- -q ; question marks for nongraphic characters :
180
- when directory is not "executable" :
244
- lslpp , getting XLF version numbers :
318
M
- make , dependency for Makefile itself :
111
- parallel :
148
- passing macro definitions from "make" compile line through to compilers :
297
- preprocessor directives with make :
326
- man pages , adding personal man pages to search path :
186
- stripping format chars :
118
- memorization , how to remember numbers :
305
- memory for T3E compiler , getting (or not) more of it :
251
- memory utilization , determining at run-time with ja command :
190
- merging source code versions :
124
- MFLOP/S , measuring on T3E :
153
- Minneapolis , best restaurants :
170
- mkdir, -p ; making complete tree :
172
- modules (Fortran 90) , initializing variables :
199
- modules (UNICOS environment) , "module load pghpf" command :
151
- creating custom Cray Programming Environment modules :
186
- listing compilers, libs, tools, etc. and versions :
117
- trouble calling "module" in qsub script :
206
- mosquitos , repellents, traps, and head nets :
250
- MPI , how to preface stdout with task number :
255
- message tags, coordinating sends and recvs :
210
- MPI_Abort for aborting MPP jobs :
125
- MPI_Bcast vs SHMEM_BROADCAST :
195
- MPI_Comm_dup and creating your own MPI libraries :
232
- MPI_Rsend, synchronizing with MPI_Recv :
291
- using PMPI to build custom MPI subroutine timers :
382
- mpirun , "-f" option for complex argument lists :
211
- mppcore files , deleting :
107
- storing on /tmp :
114
- mppsize command :
112
- mppview , -t ; determining memory usage at runtime :
134
- mv , -i :
187
- pitfalls :
177
- moving a directory into itself :
225
N
- ndiff , diff of files, but with numerical differences allowed and handled intelligently :
378
- NetCDF , netCDF Operators (NCO) :
378
- testing the equivalence of netCDF files while allowing for differences in precision :
378
- viewing netCDF data :
327
378
- New Years Computing Resolutions :
236
- nm , show which shared library each symbol in an executable is provided by :
383
- NQS daemon :
175
- NQS job , checking stdout/stderr while still running :
217
- determining if checkpointed :
140
- preventing rerun :
119
- vanishes :
138
- automatically creating unique directory for output :
269
- numeric constants , declaring in Fortran 90 to be of a particular type :
215
- numerical precision, numerical precision and roundoff error summing real numbers :
366
O
- OBJECT_MODE , running ar command on 32 and 64 bit libraries on IBM systems:
333
- od , -c ; viewing files :
180
287
337
- -t ; display binary data converted to standard types :
365
- OpenMP , Permissible C/C++ "for" loops :
253
- SINGLE vs MASTER comparison :
212
- optimization level defaults , Cray, SGI, IBM compilers :
235
- OS version number , discover using "uname" command :
204
P
- parallel make :
148
- parallel random number generation :
133
- passwords , invent and remember :
131
- remembering :
324
- PAT , T3E performance analysis tools :
153
- PATH , listing one path per line in a colon-delimited list of paths :
265
- pathhow-compiled , Pathscale compiler option to determine, from the executable, what compiler flags were used :
368
- PBS_O_WORKDIR , testing if set :
319
- performance improvement , general advice :
166
- perl , map :
358
- script for condensing a file :
116
- ".." ; ranging operator :
163
- -e ; entering script on command line :
163
265
- -p -i ; edit files in-place, assumed loop :
126
208
274
304
- evaluating math expressions found in a text file, and s///e :
285
- examples :
241
262
265
287
304
322
329
356
357
358
370
375
- extracting fields from ls output :
356
- recovering from an untar in the wrong place :
357
- Schwartzian transform :
375
- slurp mode :
371
- perl regular expressions , minimal, or non-greedy, matching :
262
358
- look-ahead assertion:
358
- perl xdump , read binary files and convert :
365
- PEvers (programming environment components) :
117
- pghpf , accessing man pages :
151
- Pi , getting machine precision value for Pi in C/C++ and Fortran programs :
263
- postscript to png image conversion , ImageMagick, gs, gimp, Netpbm, pstopnm, and ps2png :
374
- preprocessing , cpp examples :
260
339
- program memory usage , how to determine :
134
137
- ps , -p $$ ; to determine which shell I'm using :
294
- extracting grep process from grepped output :
224
- python , "/usr/bin/env python" searches PATH for python binary :
372
- calling C/C++ from :
344
349
- evaluating math expressions found in a text file :
285
- examples :
375
- extracting matched patterns from lines of input :
358
- glob module :
385
- set type in python :
362
Q
- qalter , altering NQS requests at run-time :
150
- qdel , deleting a list of jobs :
381
- qsub , -j ; job log :
140
- -l mpp_t ; MPP time :
136
- -l p_mpp_t ; MPP time per process :
136
- -nr ; no restart :
119
- -ro ; check stdout while job still running :
217
- chaining a sequence of jobs :
150
- specifying shell to use :
206
- starting batch job in directory from which it was submitted :
198
- quota , how to locate all your big files so you can move or delete them :
259
- quotes , controlling the interpretation of regular expressions :
280
R
- read , example of shell read construct :
356
- remap keyboard , "enlarging" a too-small key on the keyboard by remapping it :
352
- rename , renaming files :
322
385
- reset , command for rescuing corrupted terminal session :
361
- rm , -i and -f, using together :
270
- deleting a file named "-i" :
102
- disabling "rm *" (while otherwise allowing "*") :
355
356
- preserving files which match a wildcard expression, deleting the rest :
179
301
- rmdir , -p ; deleting directory tree :
172
- roundoff error , numerical precision and roundoff error summing real numbers :
366
- rsync , using rsync to preserve file ownership and group settings during file transfer :
364
S
- scp , copying directories recursively :
343
- scp -p option to preserve dates during transfer :
314
- using remote environments with scp :
340
- scurvy, avoiding , Tips for impoverished students :
369
- search and replace , as smart as you want, across many directories and files :
208
- removing unwanted octal and extended ASCII codes from text files :
287
- SecurID Card , handling & storing :
160
- generating a sequence of valid codes w/out reentering PIN :
196
- obtainin a new PIN :
201
- sed , examples :
139
216
241
283
290
304
315
322
323
329
349
- search replace on slew of files :
304
- seq , using seq with ksh :
354
- shell , appending to the settings of existing environment variables, like PATH :
245
- expansion of wildcard characters :
216
225
256
- how to determine which shell I'm using :
294
- prompt and PS1, favorite settings for your shell prompt :
349
- sh script to reformatting number strings with commas :
329
- shell aliases -- reader favorites :
146
- syntax for conditional tests, "[" versus "[[" versus "test" :
348
- SHMEM , SHMEM_BROADCAST vs MPI_Bcast :
195
- shmem_fence vs shmem_quiet :
194
- sort , Unix sort examples :
281
316
337
- sort methods compared :
141
- sorting , sorting when the key field can be pattern matched, but isn't normally delimited :
375
- sorting words on one line :
152
- Sourdough Sam Math contest :
165
- squeezing text :
116
- ssh , using a ssh configuration file to create machine aliases :
353
- Stack frame size too large , SGI f90 warning :
202
- stat , detailed inode listins :
356
- static memory allocation , determining :
137
- stderr , piping both stderr and stdout with csh and ksh :
335
- sticky bit :
109
- strings , Unix command :
168
- stty erase :
110
- SV1 , disabling caching :
209
- SWIG , connecting C/C++ to python :
344
349
T
- table of squares , using recurrence to compute quickly :
286
- tabs , replacing with spaces :
203
- tar , adding selected files only :
377
- archiving specific files only :
331
- extracting specific files only :
323
- moving everything accidentally untarred in the wrong directory somewhere else :
357
- relative untar (remove leading "/'s") :
184
- transferring directories between systems using tar with stdin and stdout :
343
- using tar to preserve file ownership and group settings during file transfer :
364
- why is tar file 3x expected size from "du -sk" :
267
- tcsh , command completion in tcsh :
353
- disabling "rm *" with "set rmstar=1" :
355
- tee , piping stderr and stdout to a file and displaying on the screen :
335
- test , shell syntax for conditional tests, "/usr/bin/[" versus "/usr/bin/test" versus "[[" :
348
- tips for life , from readers :
185
306
- warming your car when it's cold :
334
- tips for students , milk crates :
369
- paying bills :
369
- tmp and scratch purgers :
177
- totalview , expanding fortran automatic arrays :
243
- viewing C arrays :
145
- touch , -r ; copying file access and mod time :
231
- tr , translate command, example :
140
152
316
337
356
375
U
- uals , extracting fields from ls output :
356
- finding files newer than a specified age :
377
- ulp , What's an ulp? Or, Unit of Least Precision :
254
- uname , print system info (hostname nodename release version hardware) :
204
- uniq , Unix uniq command, examples :
316
362
- unique directory name , generating automatically in scripts :
269
- Unix , finding path of an executable :
183
- Unix commands , giving arguments that start with "-" and could be construed as options :
226
- Unix vacation program , automatic e-mail reply :
143
V
- version control , maintaining software in collaborations :
278
- vi , "!" and ":" commands, how to use registers to edit, save, and execute again :
173
379
- "|" jump to column :
115
- :%s,/lib ,/usr/lib , ; using characters other than "/" to delimit search/replace :
266
- :%s/^M//g ; removing CTRL-M characters :
139
- :.,'m s/^/C ; commenting-out blocks of Fortran code :
104
- :10,30s/.\{25\}/&|/ ; inserting vertical lines :
142
- :f ; renaming file buffer :
193
- :r ; using file insertion to prepend a file to current file :
302
- ex commands :
104
302
379
- finding cursor column :
115
- generating and loading a list of files from grep:
103
- noautoindent ; fixing staggering paste :
122
- regular expresion to switch order of element within a line :
274
- "yank" from file 1 and "put" into file 2 :
252
- vim , "&" repeats last ":s" command :
379
- autocmd, remember cursor position and other state between sessions :
336
- making color schemes :
328
- register ":" contains last ":" (or ex) command. "@:" executes it again :
379
- replace :
330
- setting highlight colors :
328
W
- web browsers , obtaining URL of a frame in Netscape, IE, Lynx :
227
- wget , command-line retrieval of web pages :
311
- what command , probing executable :
108
168
- WHERE construct in Fortran 90 :
205
X
- xargs , -l ; using with find and grep :
283
- examples :
283
301
304
322
- preserving files which match a wildcard expression, deleting the rest :
301
- xlf , -qreport -qlist ; loop, optimization, and other listings :
309
- -qsuffix ; IBM Fortran compiler, recognizing .f90 files as Fortran 90 :
246
303
- -qsuffix ; Running the preprocessor on files with arbitrary suffix :
303
- getting XLF version numbers :
318
Z
- zsh , command completion in zsh :
353
- disabling "rm *" :
355
- loops in zsh :
354
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